虚幻引擎5.8版本说明

新内容

虚幻引擎5.8版本将继续完善UE5工具集。 此版本优化了多个方面，包括渲染、角色与动画、世界构建和程序化内容生成（PCG）等。

此版本包含我们的虚幻引擎开发者社区在GitHub上提交的改进。 感谢虚幻引擎5.8的每一位贡献者：

ABostrom, adam-struge-cdpr, AHGS-Jens, AlexanderVeselov-arm, alexdjq, AlexKenkenbergMetrea, Almax27, AMcClean97, Armageddon-15, aziogroup, ben-mkiv, BibbitM, BlackMATov, BlueMountainsIO, bohdon, byjtew, byte-warlock, cneumann, ColinGulliver, daktor, Damon3000s, Darcy3000s, davidesocol, dman82499, dthex5d, dyanikoglu, dzianisbutsianouski-cdpr, Edstub207, Epiphane, erebel55, Erlandys, filipkoperski, funfoofi, gamethread, Gearbox-SFatnassi, h13jc, HSeo, hugebug4ever, Iannis623, iniside, intvoker, Itotallyhavememes, ivorne, jacksonhvisuals, Jal1338, jdamdami, jeremy-skymap, JiayinCaoNV, JonnyTsGitHub, jorgenpt, JRProdSD, KaizerDragomir, kiruru002, kjohnsonTNM, kroopson, kumikai-nick, l-t-m-f, lapislosh, lclara-BARB, leeejongmin, LightKL, luciddream-tsin, Maigo, MarkJGx, Marvelius, megesdal, melku, mfgoleleka, microneo, mikeseese, mrobitaille-riot, Murazaki, nils-soderman, nrs-cerickson, Ogniok, pafuhana1213, peterschusteratms, PICO-XR, pigi5, PR3C14D0, ProdigyThirteen, PushStartInteractive, rdunnington, RedFlowering, redxdev, Riopho, riotcam, RKIV, rmatteson-riot-personal, rokenrock, ronaldogsk, Sage-of-Mirrors, sareali, SimonLeeGit, skokon, Skylonxe, slonopotamus, SoulSharer, SRombauts, ssutherland-riot, TeamBaconn, TheJSLo, tomilov, Vaei, Variann, VesCodes, x380kkm, yaakuro, yangskyboxlabs, yicwang25, zompi2

渲染

Megalights

Megalights现已进入虚幻引擎5.8的生产就绪状态。 我们大大降低了噪点，以最大化实现视觉保真度，同时提高了整体性能以实现60fps。 我们还引入了新工具，帮助调试和优化你的场景。

功能支持

• 透射支持（次表面散射）

• 新增基于Froxel的半透明度支持

• 高质量前层半透明光照

• IES对体积和半透明的支持

• 光照通道支持

• 云阴影

• 第一人称视角武器支持

可视化视图

• 光源查找器工具（调试和优化）

• 光线查看器工具（光线迭代次数）

• 阴影投射器和阴影投射器不匹配视图

有关此功能的更多信息，请参阅MegaLights。

Lumen Lite（测试版）

Lumen Lite是Lumen支持的一种新的中等质量全局光照设置，使用辐照场并支持Probe Occlusion。 它的速度是Lumen高质量模式的两倍，在PlayStation 5上可实现60fps，同时仍能保持依赖全局光照的游戏的美术风格。 这条路径是当前一代掌上游戏机的新默认设置，在掌机上能够以60fps运行，并且也支持PC平台。

有关此功能的更多信息，请参阅Lumen Technical Details和Lumen Performance Guide。

将X-Rite的AXF材质作为Substrate材质

凭借Substrate材质系统，我们正在添加将X-Rite的AxF格式的已测量材质导入到虚幻引擎的支持。

这一功能支持汽车和工业可视化团队将从X-Rite Pantora导出的高保真、真实世界扫描材质直接导入到虚幻引擎中。

FSSS - 雾屏空间散射（实验性）

虚幻引擎5.8引入了一项实验性的雾屏空间散射（FSSS）功能，该功能位于指数高度雾组件上，可近似参与介质中的多重光散射——通过模拟光在体积效果中的散射方式，使浓雾、烟尘看起来更模糊，提高与场景的融合度。

它支持所有体积雾和局部雾体积，并提供可配置的控制选项，用于场景颜色集成和散射范围，但尚不支持体积云和异类体积。 这是一项实验性功能，目前仅提供单一的模糊质量级别，并且可能出现视觉伪影。

Substrate NPR着色（实验性）

在虚幻引擎5.8中，我们引入了实验性的Substrate Toon Shading，这是一种基于Substrate Blendable GBuffe（旧版）模式的风格化非真实感渲染解决方案。 它支持所有光源类型，包括局部光源、天空光源和Lumen全局光照，并能通过新的Substrate Toon BSDF和Toon配置文件资产，为漫反射和镜面反射响应提供精确控制。

Substrate NPR着色功能包括：基于渐变的漫反射和镜面反射控制（带抖动）、带影线的自阴影消散、各向异性镜面高光和全局光照比例控制。

角色和动画

模块化控制绑定改进

在虚幻引擎5.8中，我们重点改进了模块化控制绑定的稳定性和日常可用性。 这些更新解决了层级管理、模块创作、连接器工作流和镜像行为中长期存在的摩擦。

显示

• 新的仅显示空插槽视口选项，简化了模块的拖放操作，并有助于在模块顶部构建插槽。

层级和状态持久性

已提高绑定和模块层级的可靠性和一致性：

• 骨骼层级和模块层级现在可以在编译后可靠地保留状态。

• 已修复一个问题，即在绑定模块中与类设置交互时可能导致绑定层级消失。

• 已解决撤销/重做操作可能清除整个绑定层级的问题。

• 模块化层级筛选设置现在可在不同会话之间保持不变。

• 已修复选定的控制项在编译依赖模块后可能保持卡顿状态的问题。

• 蓝图视口的显示状态现可在重新启动编辑器后保持不变。

• 模块绑定类字段现在同时显示资产名称和完整的资产路径。

• Shift键点击和鼠标中键点击现在可以展开或折叠模块层级中的子项。

• 模块层级树现在更紧凑、更易读。

• 当模块类列可见时，模块层级搜索会将模块类纳入搜索范围。

• 已添加用于显示或隐藏连接器和模块类列的选项。

• 已添加热键，用于显示/隐藏模块层级中的可选、次要和未解析连接器。

模块创作和创建流程

优化常用创作流程，提升功能的易发现性：

• 现在，在模块层级中右键单击即可复制模块。

• 已添加用于复制模块的热键。

• 拖放模块现在可自动启用构造图视图。

• 将控制绑定模块添加到创建控制绑定资产菜单中。

• 已添加用于创建新插槽的热键。

连接器系统改进

显著改进连接器的易用性，并增强规则处理能力：

• 现在，可以在模块化绑定编辑器中的下拉菜单中选择形状类型。

• 在控制绑定模块中定义的连接器描述现在显示为工具提示。

• 数组连接器重新排序操作柄现在默认可见。

• 不可拖动的连接器会显示插头图标，并通过工具提示显示连接状态。

• 启用从细节面板直接拖放连接器。

• 已支持在层级中显示/隐藏连接器和模块类。

• “全部删除”现可正确清除细节面板中的数组项。

• 已修复无法从数组连接器中删除所有连接的问题。

• 已修复非数组连接器在细节面板中错误地显示为数组的问题。

• 已添加对连接器数组的最小/最大规则支持。

• 已添加对连接器数组的设置默认匹配支持（支持单个连接器和通配符数组）。

• 已启用向空数组连接器添加默认目标。

• 已阻止层级和细节面板在编辑数组连接器时完全刷新。

• 已改善连接器在复制带有子模块的模块时的解析方法。

• 连接器选择现可正确遵循模块详细信息中的连接器规则。

• 已修复在控制绑定模块中编辑连接器规则时发生的罕见崩溃。

镜像改进

• 模块化绑定现在可保留镜像输入设置。

• 镜像模块现在可以正确镜像子层级和多选内容。

骨骼编辑器混合形状绑定工具

绑定和混合形状工具

虚幻引擎5.8中增强的面部绑定和变形目标编辑工具扩展了骨骼编辑器和控制绑定，以更好地支持雕刻驱动的面部工作流程。 这些改进增强了引擎内混合形状的创作功能，可用于风格化角色、自定义骨骼网格体和 MetaHuman。

• 蒙皮工作流期间的关节锁定支持。

• 针对变形目标的网格体元素选择和编辑，支持软选择。

• 镜像（对称）变形目标的热键。

• 翻转变形目标的菜单选项。

• 新工具，可使用顶点贴图将变形目标拆分为两部分。

• 用于编辑变形目标的点阵变形器。

• 用于LOD生成的后处理几何体脚本（启用简化的细分样式工作流）。

• 更一致的移动笔刷行为。

• 基于表面的画笔衰减。

我们对骨骼编辑器工具进行了易用性改进，以提高稳定性、可用性和制片工作流程。

选择

• 退出“隔离所选”后保留顶点/组件选择。

• Ctrl+点击按钮可切换到新的选择模式。

• Shift+点击按钮可修改现有选择。

• 直接从权重组件编辑器中选择骨骼。

• 与资产编辑器的新统一小工具系统集成。

蒙皮和权重编辑

• 已修复在骨骼上添加权重时未能正确更新骨骼树的问题。

• 已更新权重绘制渐变控件。

• 权重工具获得显著改进，并与混合形状工作流开发保持一致。

• 新的蒙皮权重锁定功能。

  • 调整两个影响源之间的权重，而不影响其他权重。

骨骼编辑

• 镜像字符串现在可在骨骼名称的任意位置生效。

• 支持跨层级镜像关节。

• 已修复骨骼重命名问题。

• 已修复折叠层级时骨骼树子项选择的可见性问题。

• 轴下拉菜单不再错误地允许选择“无”选项。

• 已添加局部旋转轴（LRA）调试显示。

• 已添加“仅定向选定骨骼”选项。

• 已添加“选择性粘贴”选项，用于在资产之间传递关节。

• 已将网格体和骨骼菜单移至顶部视口工具栏。

网格体和变形编辑

• 已添加基础网格体和变形目标的基本网格体元素编辑功能。

  • 当前支持移动选定元素。

  • 为扩展编辑功能提供基础支持。

骨骼数量削减工具

• 从骨骼网格体中移除未使用骨骼的新选项。

  • 移除未被皮肤权重引用的骨骼。

  • 保留到根节点的父级层级结构。

使用控制绑定物理效果实现动画效果（Beta版）

控制绑定物理效果进入Beta阶段，本次发布引入了新的基于力的功能，并扩展了工具集，以支持更偏物理驱动的动画工作流。

物理绑定现在表现为分层绑定，可以自然地叠加在现有动画之上，无需明确的分层绑定设置。

这些更新提升了绑定的创作流程以及面向动画师的使用体验，尤其是在模块化控制绑定中效果更为显著。

新内容：

• 支持在控制绑定物理效果内直接施加力。

• 能够随时间对作用力进行动画制作，以实现动态绑定行为。

• 运行时性能优化。

• 改进了“alpha”的工作方式，使其能够在模拟和直通之间进行混合。

• 模块化控制绑定的新物理模块，可简化物理设置。

• 动画师工具包中新增物理辅助控制绑定，用于协助处理物理驱动绑定。

这些改进扩展了基于物理的绑定的创意范围。

动力学——控制绑定的粒子物理系统

控制绑定动力学是一个新的、轻量级、基于粒子的解算器，直接内置于控制绑定中，用于实现高性能的游戏内角色模拟。

该插件专为衣服、毛发和配饰等装饰性元素设计，可提供快速且可编辑的物理效果，无需依赖完整物理引擎的额外开销。

新内容：

• 新的控制绑定动力学插件，带有专用的基于粒子的解算器，专为实时性能而打造。

• 相比现有物理解决方案，运行时性能提升5倍。

• 更少的节点和简化的创作工作流程，可降低设置复杂性。

• 专为游戏内装饰和物理驱动的角色资产而设计。

控制绑定动力学为技术动画师和绑定师提供了一条快速、实用的角色物理模拟实现路径。

使用直接网格体控制实现动画效果（实验性）

直接网格体控制（DMC）使控制绑定控制项能够直接显示在骨骼网格体分段上，让动画师能够通过与角色的表面进行交互来操作绑定。 这引入了一种新的控制范式，用于补充传统的静态形状控制。

• 创建基于网格的控制组，用作控制绑定的控制功能。

• 在视口和Sequencer中直接选择和操作网格区域。

• 与传统静态形状控制共存，适用于不适合使用网格体控制的绑定（例如，尾巴或机械绑定）。

• 视口驱动的点击并拖动交互，可实现更快的对象和绑定操作。

筛选和链接系统

我们同步了Sequencer、曲线编辑器和视口之间的选择。

• 现在，视口、Sequencer和曲线编辑器之间的选择已完全同步。 点击视口中角色上的控制点，在Sequencer大纲视图中选择一个轨道，或在曲线编辑器中选择一条曲线——这三个面板会同时即时更新。

• 你的所有筛选器和搜索现在也已默认相互关联。 因此，你在其中一个编辑器中所做的任何操作都会同步到另一个编辑器中。

• 新的链接图标可让你决定是否需要这种链接行为。 在未链接状态下，可自由选择在任一视图中查看的内容。

Sequencer的简洁视图

Sequencer现在可以折叠成简化视图，使动画师在制作动画时能够专注于视口的特定区域。

• 将Sequencer视图折叠为简化的时间轴，显示以下关键帧：

  • 已选中并固定（任何已固定的轨道 + 已选中的Actor/控制点）

  • 已选定 (已选择的Actor/控件)

  • 全部（Sequencer中的所有内容）

• 随时将简化时间轴展开为完整的Sequencer视图

  • 简化热键（Ctrl-退格键）

  • 隐藏工具栏的热键（shift-退格键）

• 功能

  • 选择多个关键帧

  • 移动、缩放、复制/粘贴、删除

  • 帧对齐和智能对齐支持

• 为角色动画制作而精心优化的工具栏

  • 添加/删除中间帧

• 选项

  • 网格色块

  • 显示/隐藏工具栏、传输控制、范围滑块

  • 自定义颜色、外观、样式

Sequencer自动烘焙

我们添加了新的工作流程，用于自动烘焙到动画序列，以及在烘焙数据和实时控制绑定数据之间来回切换。

• 已在右键点击菜单中添加一个新的配置自动烘焙选项。

• 允许利用链接动画序列工作流。

• 已为所有启用此自动烘焙配置的项目添加快速切换图标。

Sequencer中的动画混合（实验性）

在5.6版本中对过场动画无缝游戏玩法切换所做工作的基础上，动画混合器进一步增强了影视动画师在Sequencer中直接混合不同动画输入的能力。 这为过场动画美术师提供了一种对序列中的角色动画进行分层和遮罩的方式，而无需单独的动画蓝图或特定插槽。 动画混合器还支持新虚幻动画框架的工作流。

你可以使用它来执行以下操作：

• 创建动画混合器，并将其分配给动画蓝图插槽或自定义动画实例。

• 创建混合图层，用于按优先级顺序分层骨骼动画、控制绑定或任何影响骨骼姿势的输入。

• 在任意混合层上使用混合遮罩资产遮罩骨骼和曲线。

• 向任何混合器、图层或分段添加修改器，以进行骨骼匹配、偏移根运动、镜像等操作。

• 在动画之间添加过渡，例如交叉淡化或死混合。

用于重定向的足部定义

针对虚幻引擎5.8，我们继续改进IK重定向器，以将足部动画传输到各种角色。 专注于运行时重定向和动作捕捉工作流的动画师，可以借助这些新功能，在将动画重定向到不同角色时，更有把握地获得出色的效果。 更多信息，请参阅重定向器操作堆栈文档中的足部设置。

• 为目标角色定义脚平面和脚趾，以便更好地控制转换。

• 已更新重定向链的自动重定向模板，用于足部定义。

• 额外控制，防止较矮角色的垂直骨盆运动减弱

• 混合到源、缩放目标和偏移目标在IK操作栈中被拆分出来，以便加更灵活地进行排序。

重定向重载集

针对Gameplay重定向工作流，重定向重载集让单个IK重定向器资产能够处理不同的重定向关系，无需额外创建资产或额外的蓝图逻辑。 更多信息，请参阅IK绑定重定向文档中的重载集。

• 创建操作及其属性的集合，并将其存储为重定向器资产中的重定向重载集。

• 添加并继承现有重载集，以实现更灵活的重定向。

• 将操作和/或其属性绑定到重载集中的动画曲线或变量。

• 设置在执行IK重定向器时所使用的重载集，可用于运行时重定向或离线重定向。

有关此功能的更多信息，请参阅IK Rig Retargeting。

RigMapper动画重定向工具（测试版）

我们正在继续改进绑定映射器，提升节点图表的创作能力，并进一步集成到IK重定向器中，以处理更完整的面部动画传输。 它提供了一种在不同角色设置之间传输动作的方式，例如将ARKit动画应用于MetaHuman，或将MetaHuman Animator（MHA）动画应用于ARKit角色。

我们将重映射曲线扩展为一个操作堆栈，以按优先级顺序处理所有曲线重定向操作。

• 之前的5.7工作流现在通过用户数据绑定映射器操作得到支持，该操作按数组顺序处理绑定映射器评估。

• 我们提供了一个新的单绑定映射器操作，供用户分配单绑定映射器定义。

  • 在重映射曲线堆栈中创建多个单一绑定映射器操作，以确定评估的优先级顺序。

• 我们扩展了绑定映射器定义编辑器的节点图表行为，以提供更好的用户体验：

  • 从上下文菜单或通过拖放引脚创建新节点。

  • 根据上下文和方向，在节点之间拖动和连接引脚。

  • 移动和排列节点组。

  • 已更新每个节点的细节面板，支持在图表中实时查看编辑操作。

Mutable

Mutable 在UE 5.8版本中达到生产就绪状态，稳定性、性能和管线均有所改进。

无数据可自定义Object实现了运行时驱动的参数处理，从而加快了迭代速度，提高了图表的可复用性，并改进了修补功能。 它们经过优化，可用于网格体操作和简单的纹理合成。

无数据工作流提供了一种在运行时而非编译时评估参数输入的方式，显著降低了迭代成本，同时保持了与虚幻引擎打包和加密系统的兼容性。

骨骼网格体引脚简化了常见工作流程，让用户能够在骨骼网格体层面（而不是网格体分段）进行操作。

我们对性能进行了全面改进，包括并行更新以提高人群的生成吞吐量、减少游戏线程工作负载以及优化网格体和纹理操作。

有关此功能的更多信息，请参阅Mutable骨骼网格体生成。

Live Link Face视频流送

iOS和Android上的Live Link Face现在可以直接向虚幻引擎实时传输视频，让现场主管和导演能够实时监控演员的表现。 视频流与虚幻引擎媒体描述文件集成，支持查看捕获的素材和已解算的动画。 在较新的设备上，视频流和实时动画解算可同时运行。 该流媒体传输功能专为低带宽、高延迟的Wi-Fi网络环境设计，能够提供可靠的运行表现。

MetaHuman

使用MetaHuman人群填充你的世界

组装经过优化的MetaHuman角色实例，以创建与Mass兼容的人群，将角色数量从数十个扩展到数千个。 全新的实验性MetaHuman人群插件提供了一套完整的组装流程，可根据摄像机距离在高保真的独立Actor与低保真的实例化骨骼网格体之间实现无缝过渡。

重要功能：

• 构建模块化组件（头部、身体、毛发、服装）的集合，并使用蓝图手动或程序化地进行组合。

• 优化的面部纹理，减少内存占用的同时保持视觉保真度。

• 根据距离远近，使用虚幻动画框架动画框架或简单的序列制作动画。

• 使用Mass模拟，使用Nanite或动态LOD系统渲染。

• 示例项目设置单独提供，适用于所有虚幻引擎目标平台。

有关此功能的更多信息，请参阅MetaHuman人群。

MetaHuman Creator

将全身网格体转换为MetaHuman角色，准备制作动画

只需一个工作流程，即可将具有任意拓扑的任意人体角色网格体转换为完全绑定骨骼的MetaHuman。 改进后的Mesh to MetaHuman流程可同时拟合头部与身体，支持任意拓扑结构的输入网格体，并由MetaHuman数据库自动生成结果。

重要功能：

• 在单个步骤中同时完成头部和身体的拟合。

• 支持任何拓扑结构的头部和/或身体网格体作为输入。

• 为人类角色提供自动结果，并提供手动控制以进行技术修正。

• 适用于通过扫描、外部GenAI/DCC工具或现有角色转换创建的角色。

有关此功能的更多信息，请参阅从自定义网格体。 

充分控制未烘焙纹理，以实现更高的保真度或另类视觉风格

组装MetaHuman角色，不使用烘焙材质和纹理。 这使得美术师能够进行精细的外观开发和纹理控制，从而帮助他们实现特定的外观效果。 使用标准的虚幻引擎编辑器创建未烘焙的纹理和材质资产，或将纹理导出到外部DCC工具。 MetaHuman Creator提供了相应的选项，支持使用用户自定义的纹理和材质重载。

重要功能：

• 完全控制纹理和材质，以实现自定义的视觉保真度或审美风格。

• 修改后的未烘焙材质和纹理可作为重载项，应用到MetaHuman Creator中，使用户在使用默认组装配置时仍能获得材质烘焙带来的优势。

• 使用熟悉的资产编辑器实现标准的虚幻引擎工作流程。

• 用于外部DCC创作的导出功能。

应用场景：在保持性能优化的同时，实现超出MetaHuman Creator内置功能范围的角色外观效果。

更多信息，请参阅未烘焙材质。 

使用你的光照设置预览MetaHuman角色

在MetaHuman Creator中创建自定义光照场景，以在目标环境的背景下预览角色。 定义光照配置时可使用模板，这些模板包括天空半球、后处理体积和光照组。然后使用这些自定义场景，在创作过程中验证视觉保真度。

重要功能：

• 直接在MetaHuman Creator中预览目标光照环境中的角色。

• 缩小MetaHuman Creator预览效果与关卡内实际表现之间的差距。

• 检查并修改视口渲染设置，以实现精确控制。

• 适用于角色美术师、光照美术师和视觉开发团队。

• MetaHuman Creator视口现在也完全支持Lumen。

更多信息，请参阅Custom Lighting Scenarios and Render Settings。 

MetaHuman Animator

从单台摄像机捕捉身体动画

使用一台摄像机捕捉一位演员的身体表演，或面部和身体表演。 这项全新的实验性功能将MetaHuman Animator的应用范围从面部扩展至身体，为内容创作者消除了光学动作捕捉环节这一障碍。 在Fab上作为独立插件提供，并直接集成到MetaHuman Animator中，Live Link Face移动应用程序也已更新，支持同时进行身体和面部捕捉。​

重要功能：

• 使用一台摄像机即可对一名演员进行身体捕捉，并可选择同步进行面部捕捉。

• 离线解算以获得高保真效果。

• 兼容多种消费级硬件，包括网络摄像头和受支持的智能手机。

• 可通过Fab作为独立的MetaHuman Animator无标记动作捕捉插件使用，并作为MetaHuman Animator的一项功能集成在虚幻引擎内部。

• 文档中包含详尽的捕捉指南

有关此功能的更多信息，请参阅使用单目视频制作动画。 

MetaHuman Animator已优化批量处理

借助优化的API，MetaHuman Animator现在可批量处理大量捕捉表演数据。 更新后的工作流程涵盖了从解算到动画审核及导出的完整端到端管线。 我们将提供参考蓝图示例，用于扩展或自定义你的特定管线。

MetaHuman Animator现已支持Linux和macOS

MetaHuman Animator现在支持Linux和macOS，扩大了虚幻引擎编辑器和MetaHuman Creator在各个平台上的可用性。 你可以在Linux和macOS上基于动作捕捉生成面部动画，无需借助Windows设备。 但是，身体动画功能目前仅支持Windows。

重要功能：

• Linux和macOS支持离线和实时面部MetaHuman Animator功能。

• 平台表现与虚幻引擎编辑器和MetaHuman Creator一致。

• Linux上的实时面部动画仅支持使用Live Link Face。

已改进MetaHuman Animator解算和曲线质量

全新的实时和离线动画模型可在更广泛的捕捉条件下提供更高的解算质量，包括不同的摄像机角度、镜头畸变和红外照明。 音频驱动动画借助全新的实时模型获得改进效果。 曲线输出对动画师更友好，关键姿势的激活更简洁，便于编辑和优化。

世界构建

网格体地形（实验性）

下一代基于网格体的地形解决方案，支持使用3D建模、分层、虚拟纹理、通用编辑器工具、可变曲面细分和Nanite技术构建大型世界。 此功能旨在取代并消除虚幻引擎中当前仅依赖高度场的地形解决方案的典型限制。

有关此功能的更多信息，请参阅网格体地形。

快速几何体流送（实验性）

快速几何体流送插件在5.6初始版的基础上，新增了针对速度、稳定性及用例支持的多项改进。

• 新增贴花、点光源、聚光源和矩形光源组件支持。

• 在静态网格体组件中增加了对网格体绘制纹理的支持。

• 在IPhysicsBodyInstanceOwnerResolver中增加了更多功能：

  • 获取碰撞对象类型

  • 获取碰撞启用状态

  • 获取变换

  • 根据ID获取物理对象

  • 获取所有物理对象

• 修复了变换过程中被忽略的非图元组件。

• 修复了FastGeoContainer不含任何物理效果的问题。

• FastGeoStreaming.ini现在是DefaultFastGeoStreaming.ini。

• 现在，当FastGeo运行时单元变换器为变换后的组件创建新的替换根组件时，会保留根组件的移动性。

• 修复了运行PIE和弹出玩家时，图元错误显示的问题。

• 修复了编辑器中的一个MT问题。

• 删除了未使用的EProxyCreationState::Pending和UFastGeoComponentEditorProxy。

• 通过重构简化了快速几何体组件的接口，并使其更加清晰。

• 修复了WorldPartitionRuntimeCellTransformerISM为无法完全变换的蓝图Actor复制实例的问题。

本次实验性版本还包含多项针对崩溃、线程、死锁和初始化的额外修复。

世界分区Insights

我们为Unreal Insights和虚幻编辑器添加了世界分区流送调试工具，可实现按单元分析和会话回放。

HLOD用户体验

我们对世界分区中的分层细节级别（HLOD）做了以下改进。

功能：

• 新增批量删除操作，以减少源码控制开销。

• 现在支持在放置同一个子世界分区关卡的多个实例时使用独立HLOD。

• 新增了一个感知差异启发式选项，可仅在需要时更新HLOD。

• 增加了在编辑器中直接从关卡构建HLOD时对新Actor和已删除Actor的支持。

用户体验：

• 为选定项构建HLOD。

• 通过世界分区编辑器为所选区域构建HLOD。

程序化内容生成（PCG）

手动编辑

在虚幻引擎5.8中，我们新增了PCG数据和资产的非破坏性手动编辑功能，支持选择、排除、修改以及数据恢复。

图表中的各个节点可以标记为手动编辑或暂时重载。 新的数据重载窗口会列出应用于被检查节点的所有重载项。

复杂属性

现在支持将数组、结构体、集合及映射用作元数据属性值和重载。 这包括提取结构体和数组中数据的各种操作以及数组操作。

新增的“创建复杂常量（Create Complex Constant）”和“添加复杂常量（Add Complex Constant）”节点可在PCG图表中配合复杂类型的图表参数一起使用。

嵌入式子图表

新增对创建自定义子图表的支持，类似于蓝图函数，可直接在PCG图表中存储和编辑。

图表参数编辑器

现在，你可以在全新的参数层级编辑器工具中对PCG参数进行分类、排序、分组和描述。

PCG性能

运行时：

• 现在，PCG GPU运行时散射与地形GPU草地系统的性能范围相同，并且已在所有平台上进行压力测试。

• 无Actor/无组件运行时生成

编辑器：

• 优化了运行图表时的CRC和缓存过程，降低了缓存失效的可能性，提高了效率。

• 改进了生成大量静态网格体时的ISM重用逻辑。

• 改进了图表执行和调度，消除了争用和瓶颈。

PCG用户体验

PCG用户体验持续改进，最新变化包括：

• 上下文筛选：从任意类型的引脚拖出以添加节点时，节点面板会自动筛选出支持的操作，并提供包含转换或完全禁用筛选的选项。

• HLSL内核：现在可直接从HLSL内核创建属性，而不是在节点设置中创建。

• HLSL编辑器：现在可设置字体大小。

• 数据视口：现在可通过PCG编辑器的数据视口编辑手动重载

PCG节点和运算符

虚幻引擎5.8引入了多个原生PCG元素和新选项，包括：

• 元数据数组操作：最实用的数组操作（创建、添加、添加唯一、包含等）。

• 对齐点：将点的位置和旋转与另一个点在任意给定轴和空间参考系上的边界对齐。

• 场景捕获：场景捕获节点现在支持输入变换，允许从任何方向进行捕获，为GPU采样增加了额外的灵活性。

• 创建/添加复杂常量：使用这些节点可直接在图表中创建或添加任何复杂属性类型。

• 将样条线应用于组件：将PCG样条线数据写入现有样条线组件引用。 适用于在编辑器中对现有样条线应用更改。

• 传送Actor和组件：提供了一种对世界中的任何Actor或组件引用应用变换的方法。 适用于新的基于关卡的PCG工作流程，可在编辑器中应用即时操作。

• 从属性获取类：从软Object引用获取类，并将其作为属性返回。

• 获取编辑器摄像机：将当前可见的编辑器视口摄像机以点的形式返回，以便用于编辑器内的各种操作。

• 在动态网格体上设置材质：将材质应用于动态网格体数据。

程序化植被编辑器（实验性）

程序化植被编辑器是一个实验性插件，可以让你直接在虚幻引擎中创建和编辑植被网格体，并且支持Nanite植被。 虚幻引擎5.8引入了一些新的核心功能，大幅扩展了PVE的能力，支持直接在编辑器中生长，无需导入配方，同时还包含大量其他改进。

• 生长节点

• 种子生成

• 从3D网格体或2D图像/图集中提取骨骼

• 植被嫁接

• Object规避和雕刻

• 修剪-分支循环、位移曲面细分

• 网格化器改进

• 可视化模式

• 主干材质合成器

有关此功能的更多信息，请参阅程序化植被编辑器。

框架

StateTree起始状态和编译器扩展

虚幻引擎5.8增强了状态树（State Tree）的灵活性。

我们改进了创作工作流程；树现在可以定义其起始状态。

新的编译器管理器有助于简化迭代，编辑器现在会跟踪树何时过时，从而更清楚地指示何时需要重新编译。

属性绑定更加稳定，现在允许轻松反转绑定，从而直接将数据从一个已完成的任务轻松转移到另一个任务。

有关此功能的更多信息，请参阅状态树。

Mass框架：更快、模块化，专为大规模应用而构建

Mass，我们的数据驱动实体系统获得了重大改进。

Mass Signals现已成为核心引擎的一部分，并且由于采用了基于原型的无锁调度，实体可以在游戏线程之外创建。 新的稀疏/虚拟片段系统可减少内存使用，并允许添加或删除可选片段和标签，而不会产生昂贵的原型更改开销。

我们彻底改进了Mass处理器执行和依赖项解析，以更好地利用多核CPU，从而在现代硬件上实现更安全、更快速的执行。 更细粒度的调度机制以及线程安全的观察者通知为其提供了支持。

新的MassCore模块通过将核心实体系统从更广泛的MassGameplay堆栈中分离出来，进一步简化了采用过程。

有关此功能的更多信息，请参阅MassEntity。

导航：按网格体级别控制可行走表面

静态网格体现在可以在导航网格体生成过程中定义自己的可步行区域，让设计师能够更好地控制AI在世界中的导航方式。 你可以为静态几何体分配每网格区域成本——例如，标记沙发以便AI绕着它走，而不是从它上面走过。

该功能通过NavCollision的标志位及区域类别设置在网格体级别启用，并贯穿整个Recast导航生成管线。

Iris：生产就绪的复制系统

Iris现已在虚幻引擎5.8中达到可供授权方使用的生产就绪状态。

在实现这一里程碑的同时，我们还增加了一系列改进措施，重点关注稳定性和日常可用性。 我们改进了协议不匹配处理，因此当与服务器不同步时，客户端会收到更清晰的错误信息，而新的警告功能则有助于更早地发现Object生命周期问题。 序列化、剔除距离处理和诊断都得到了改进，并重新启用了RPC DoS检测功能。

Iris也更贴近引擎的整体发展方向，增加了对场景图集成和RemoteObjects RPC路由的支持。

有关此功能的更多信息，请参阅Iris复制系统。

Mover：已改进物理、动画和网络功能

Mover得到了广泛更新，涵盖了Core移动、网络、动画和ChaosMover。

Core移动模式获得了一系列修复和改进，包括对Detour Crowd的NavWalking支持、针对移动平台或摇晃船只等场景的更稳定附着移动处理，以及对根运动与动画蒙太奇处理的改进。

分层移动现在可以提前安排，以实现更好的同步，同时还扩展了回滚和预测支持。

网络功能方面也得到改进，新增对网络预测Irs复制的可选支持，并引入自适应时间膨胀，以减少客户端预测前置的开销。

ChaosMover增加了动作匹配工作流程的轨迹预测功能，更深入地集成了Chaos可视调试器，并更广泛地支持模拟驱动的蒙太奇、分层移动、Gameplay标签和即时移动效果。

总体而言，这些改动持续推进Mover从实验性状态向稳定架构演进，并在移动模式、预测、重模拟以及动画驱动工作流程等方面提升整体稳定性。

统一输入系统：通用UI和增强输入

我们在虚幻引擎5.8中简化了输入工作流程，统一了增强输入和通用输入/UI。 这简化了跨平台输入处理，消除了重复数据资产的需求，并使调试过程更加直观。

本次更新还包括输入处理方面的一系列改进，包括更可靠的事件处理、更好的控件绑定行为、扩展的虚拟按键支持以及对触发边缘情况的修复。

新工具（例如增强输入UI的输入调试器和增强的可扩展性）让构建和排查输入驱动体验变得更容易。

开发者迭代

增量烘焙（实验性）

增量烘焙继续作为虚幻引擎5.8的测试功能。 对确定性的改进进一步减少了对未修改资产进行重新烘焙的需求，尤其是在DDC和结构化数据变体方面。

增量烘焙通过缩短整体烘焙时间，可加快在目标设备上的迭代速度。 烘焙流程会根据Zen服务器中存储的输出自动分析资产变化，并只烘焙项目资产的新增更新。 这适用于所有的原生引擎资产，包括蓝图和世界分区图块。

将Zenserver作为烘焙输出存储

Zenserver作为烘焙输出存储现在默认启用。 这也意味着虚幻编辑器中的工作流在设备上启动游戏/客户端时会自动使用Zenserver流送，暂存容器文件（pak/iostore）仍可用于非迭代工作流并受支持。 为确保其能与远程设备配合使用，Zenserver会响应远程请求，但前提是请求方必须提供预先生成的授权密钥。

• 在项目设置中禁用Zen存储的现有项目将不会使用Zenserver作为烘焙输出存储。 他们需要手动更改项目设置中的该设置才能启用它。

• 对于专业开发用例，项目应在DefaultEngine.ini配置文件中的Zen.AutoLaunch部分将LimitProcessLifetime设置为false，以避免Zenserver频繁启动和停止。 这需要自动化/构建流程方面的考虑，以确保Zenserver的持续运行不会干扰自动化/构建流程。

• AllowRemoteNetworkService配置项已重命名并更改为RemoteNetworkService，不接受true/false，而是使用以下值：

  • None拒绝向本地UE启动的Zenserver发出的远程请求。

  • 如果标头中包含与UE生成的密钥匹配的授权密钥，Unsecured会接受向本地UE启动的Zenserver发出的远程请求。

  • GeneratedStaticKey是默认值。

有关此主题的更多信息，请参阅将Zenserver作为烘焙输出存储和Zenserver流送。

Horde - 性能报告（试验性）

在虚幻引擎5.8中继续推进Horde Analytics工具链的改进，该功能目前仍处于实验阶段，并在作业步骤（CPU、内存使用情况）以及作业健康状态可观测性方面优化了控制板用户体验。

我们还在Horde中引入了一个新视图，该视图显示了自动化性能测试框架（APT）和性能报告工具（csvprofilers）输出的运行时趋势，突出显示了GPU/CPU时间、内存峰值使用量和卡顿报告等关键指标，以便发现回归问题。 当前该功能依赖用户具备自己的数据库存储模型。

音频

Audio Insights（生产就绪）

Audio Insights在虚幻引擎5.8中进行了重大更新，新增了功能并进行了改进，扩展了其诊断功能，涵盖响度测量、信号流可视化、实时事件监控和数据绘制，同时还对稳定性、用户体验和独立应用程序进行了大量改进。

• 响度测量：专用响度计可跟踪瞬时、短期和综合响度值，以及响度范围和真实峰值、目标最大值和削波指示器，这些值在引擎上进行处理，并流送到编辑器和独立应用程序中。

• 信号流可视化工具：新增一个选项卡，可追踪瞬时音频信号图，从源头经过子混音一路到输出设备，并在各个阶段显示混音数值，以便排查衰减或路由问题。 也显示缓存数据，用于离线取证分析。

• 时间轴缓存控制：动态控制显示播放头，以同步单个时间戳在多个数据仪表板上的数据显示。

• 控制总线和调制可见性：控制总线选项卡现在可将控制总线混合作为源与单个总线一起显示，而调制选项卡仅筛选出活动的控制总线列，以减少干扰。

• 实时监控：Audio Insights现在可以实时显示追踪数据，无需保存追踪文件，从而消除了长时间监控会话期间的磁盘空间问题。 已支持编辑器和独立版本（通过Unreal Insights）。

• 事件日志：新增可停靠的“事件”选项卡，提供实时、可滚动的时间顺序日志，用于记录声音的开始、停止及其他音频事件。 事件可通过文本筛选、按时间选择来同步其他可视化效果，双击事件可直接导航到“声音”选项卡中的相应实例。

• 绘图：专门的绘图选项卡，整合了每个声音参数的绘制，改进了渲染，修正了跟踪暂停时的颜色连续性，并修复了独立模式下的显示伪影。

• 独立和缓存改进：数据缓存管理器现在可在独立会话中工作，追踪数据可以直接从控制面板缓存保存到文件中，并且缓存大小现在可以通过设置由用户配置。

有关此功能的更多信息，请参阅Audio Insights。

音频字幕（测试版）

音频字幕无障碍功能的必要组成部分——用于对话系统、隐藏字幕以及语音聊天。 我们将插件从实验性状态升级到测试版，以反映其稳定性和功能完整性的提升。

• 字幕现在可以正确显示MetaSound图表中触发的所有声音类型，包括嵌套的MetaSound。

• 现在支持按平台字幕显示重载，允许为移动设备或Nintendo Switch等屏幕布局不同的平台，采用不同的控件位置与样式。

• 关卡序列中的字幕现在可以直接在编辑器中预览，无需进入编辑器内播放（PIE），从而加快字幕时间轴的迭代速度。

• 字幕时长现在可以按区域设置进行重载，在出现本地化资产时，自动使用对应语言声波的时长。

• 新的QueueSingleSubtitle蓝图和C++函数取代了旧的QueueSubtitle（现已弃用）。 配套函数QueueSubtitlesFromAsset在一次调用中将资产中存储的所有字幕行排入队列，并自动应用正确的计时偏移。

• 我们为字幕资产添加了一个备注字段，用于在编辑器中可见但在运行时不可见的内部备注。

• 各种用户体验改进和错误修复。

波形编辑器（测试版）

音效设计师需要强大的编辑工具，并且无需离开引擎即可完成工作。 我们正在继续改进波形编辑器，提供更精细的淡入淡出控制并优化工作流程，以减少对外部音频工具的依赖。

• 淡入淡出现在与修剪解耦。 新的淡入淡出变换允许在波形上的任意位置放置任意数量的独立淡入淡出区域——每个区域都拥有各自的淡入与淡出设置，并且完全独立于TrimFade区域。 修剪淡入淡出曲线类型现在也可以直接从工具栏设置，淡入淡出控制柄上的右键点击上下文菜单提供额外的曲线形状选项。 在淡入淡出控制柄上滚动可调整曲线斜率。

• 重新导入功能现在可以在编辑器工具栏中使用，共有三种模式：重新导入并覆盖变换（包括来自提示和采样块的标记和循环区域数据）、重新导入并保留现有变换，或者完全从新文件重新导入。

• 新的启动变换设置可帮助你预先配置当声波未包含任何变换时自动应用的变换。 这消除了标准编辑工作流程中的重复设置步骤。

• 应用变换更改时，声波的LUFS和采样峰值元数据现在会自动更新以反映变换后的波形，保持资产元数据准确，无需手动刷新。

• 标记导航的其他键盘快捷键：

  • 将播放头跳至下一个标记

  • F/B选择下一个/上一个循环标记。

  • H键将播放头对齐到最近的零交叉点。

  • 回车键停止播放并倒回至开头。

  • Shift+空格键将播放头重置到文件的开头，而不影响播放状态。

• 许多其他可用性、用户体验和UI改进。

要开始使用此功能，请参阅波形编辑器快速入门。

MetaSound节点配置（实验性）

MetaSound节点配置在虚幻引擎5.7中引入，现在虚幻引擎5.8对其进行了扩展，引入了新工具，减少了开发者的样板代码，并改善了设计师的编辑体验。

• 动态接口节点配置：新增内置FMetaSoundDynamicInterfaceNodeConfiguration结构体，可根据节点的FClassInterface定义自动管理子接口实例计数和变体类型选择。 开发者不再需要为公开子接口计数或变体引脚类型的常见情况编写自定义的每节点配置结构体——细节面板现在会自动将这些控制项显示为下拉菜单和计数字段。

• 节点更新变换API：新增更结构化的API，用于编写节点更新脚本，使开发者能够在节点接口跨大版本发生变化时，对其迁移行为进行更精细的控制。 自定义更新逻辑现在与特定的主版本关联，并在应用次版本更新和接口更新之后执行，从而确保更新顺序的可预测性。 一个迁移示例演示了这种模式：将双二阶滤波器的默认带宽从1.0更新到2.0，适用于新放置的节点，同时保留现有内容的旧版默认设置。

• 子界面布局序列化：反序列化MetaSounds时，子界面布局信息现在可以正确重构，解决了在某些平台上发生的顶点名称冲突和布局丢失问题。

• API稳定性：FClassInterface在虚幻引擎5.8中退出实验性阶段。 FNodeClassMetadata::DefaultInterface现在直接接受FClassInterface（替换FVertexInterface），并且已从IDataTypeRegistry中移除已弃用的输入/输出节点创建辅助工具。 开发者在构建节点配置集成时，可将其视为未来稳定的公共API表面。

MetaSound模板（实验性）

MetaSound模板是虚幻引擎5.8中的一项新的实验性功能，让音频程序员能够创建可复用、属性驱动的MetaSound生成逻辑，供音效设计师使用，实现快速迭代，而无需接触图表。

• 模板是一个C++定义的UStruct，它可以在设计师更改MetaSound的某个公开属性时，以程序化方式配置和重建MetaSound图表及其接口和输入。

  • 模板可以将设计师看到的内容限制为模板作者选择公开的属性；底层图表、成员列表、页面选项等可以选择完全隐藏。

  • 程序员定义了一小部分参数，他们希望设计师能够控制这些参数——例如声音列表、音高范围、滤波器截止频率，然后由模板代码负责将给定的选项配置到有效的MetaSound图表中。

• 在MetaSound编辑器中，设计师可从新模板工具栏下拉菜单中选择一个模板，并在MetaSound细节面板中编辑其属性。

  • 也支持将模板化的MetaSound转换回标准MetaSound（保留最后生成的图表状态）。

  • 模板还可以附带基于虚幻MVVM框架构建的完全自定义UMG控件选项卡，提供专用界面——滑块、预览、数组编辑器，以取代默认的MetaSound面板或与之并存。

• 虚幻引擎5.8预装了随机化器模板作为参考实现。 它从设计师指定的声波列表中随机选择，在可配置的半音范围内应用音高偏移，并支持单次播放和循环播放模式。 它在虚幻引擎5.8中默认隐藏，但可作为模板作者的工作代码示例。

格式 / 不限声道类型（CAT）（试验性）

• 完整的管线集成：CAT输出现在通过MetaSoundSource连接，这意味着MetaSound图表可以生成CAT信号并将其直接传输到音频引擎。 通过查看MetaSoundSource输入上设置的声波，可以自动确定声道格式。

• 数据定义的音频格式：自定义声道配置现在可以作为一等音频格式进行声明，并可直接在图表中使用。 这样，团队就可以定义和使用非标准或专有的扬声器布局，而无需分叉引擎代码。

• 环境立体声和转码：一阶环境立体声现在是一种内置的CAT格式。 离散格式和环境立体声格式之间的转码会在图表边界处自动处理，因此空间音频工作流程不再需要手动转换节点。

新的实验节点

• 声波播放器2.0：在CAT基础上利用实验性声音资产容器重新实现的下一代声波播放器。

• CAT混合器：用于组合图表中多通道CAT信号的专用混合节点

• 颗粒播放器：基于CAT管线构建的颗粒合成播放节点

• 乘法：乘法节点新增支持CAT感知的变体：

  • CAT 乘以浮点数

  • CAT × CAT

  多通道信号现在可以进行缩放和调制，而无需先折叠成单声道，从而能够直接在多通道总线上实现每个通道的增益、环形调制和包络整形。

• 梯形滤波器：我们移植了梯形滤波器，以处理标准AudioBuffer和CAT信号。 现有的单声道滤波器路径得以保留；CAT路径可处理多声道音频，每个声道都有独立的滤波功能。 此次转换也可作为将额外的MetaSound DSP节点移植到CAT的参考实现。

Sequencer中的音频

使用Sequencer制作过场动画、Gameplay序列和渲染的音效设计师经常遇到音频混合控制、不符合预期的默认行为，以及导出渲染的音频质量问题。 在虚幻引擎5.8中，我们将发布一系列涵盖三个方面的重大改进。

控制总线和控制总线混合轨道

• 两个新的Sequencer轨道将音频调制直接引入时间轴。

  • 控制总线轨道使任何音频调制控制总线（音量、音高、滤波器截止频率或任何自定义调制参数）都可以在序列中随时间推移进行关键帧设置和动画处理。

  • 控制总线混合轨道提供了一种在序列中的特定点激活和禁用预定义的控制总线混合（一组同时应用的调制值）的方式，从而实现与过场动画事件相关的精确且可重复的音频混合状态。

播放和分段行为优化

• 我们重新定义了音频分段的循环行为，使其更贴近典型的声音设计师的意图；用户可以定义声音是否会播放到结束，而不是在该分段结束时重复使用KeepState或RestoreState的概念，并且循环（Looping）已被重命名为重复（Repeating），以区分游戏帧边界上的分段和采样边界上的资产循环。

• 当关键帧在其范围之外添加时，音频分段不再自动展开。

• MetaSound集成使MetaSound源的回放更加可靠。

• 音频评估系统已得到改进，避免播放头上下文跳转时出现不必要的停止和重新启动，从而实现更流畅的拖动播放和暂停/恢复行为。

过场动画渲染队列音频改进

• MRQ现在支持为音频导出选择扩展的子混音，让你直接控制记录哪个子混音，而不是受限于默认输出。

• 我们修复了之前在镜头切换边界处发生的音频爆音、间隙和重复问题；音频组件现在会在切换时暂停和恢复，而不是停止和重新启动，从而消除了渲染输出中的采样级不连续性。

WASAPI

在虚幻引擎5.8中，我们将Windows上的默认音频后端从XAudio2切换到了WASAPI。 新的AudioMixerWasapi模块现在会自动选择；XAudio2仍可作为可选的备用方案。 Xbox上也使用了相同的后端。 开发者端无需进行任何更改。 所有内容都应保持相同的行为——只有与操作系统通信的层发生了变化。

作出这些改进的原因：

• 面向未来的适配与保障。 基于受支持且积极维护的Windows API，而不是旧版的API。

• 更低的延迟。 直接访问底层API，让音频混成器能够更好地控制缓冲区调度。

• 更稳定的设备处理。 WASAPI后端现在支持完整的设备切换功能——插入或拔出耳机、切换Windows默认设备，或音频驱动程序强制更改设备时，都能由引擎进行妥善处理。

• 提高质量和可靠性。 在5.8版本的开发周期中，音频团队加固了后端，以应对在生产过程中发现的一系列实际存在的设备更改、格式协商和关机等极端情况。 因此，开箱即用的Windows音频路径更加稳定。

你需要了解的内容：

• 这是一个模块，而不是插件。 WASAPI以AudioMixerWasapi模块的形式随引擎一同发布。 无需启用或安装任何内容。

• 支持设备更换。 耳机连接/断开、默认设备更改和采样率更改均由后端处理。

• 选择退出（回退到XAudio2）。 如果遇到项目特有的问题，你可以回退到之前的后端，方法是在项目的Config/Windows/WindowsEngine.ini中添加以下内容：

  Config

  [Audio]
  AudioMixerModuleName=AudioMixerXAudio2

  Copy full snippet(2 lines long)

  我们建议你报告遇到的任何问题，以便在XAudio2最终被移除之前得到解决。

平台

移动渲染器

借助虚幻引擎5.8，我们改进了移动渲染器，并在受支持的设备上扩展了更高质量渲染功能的使用范围。

虚幻引擎5.8具备以下新特征：

• 将多通道延迟渲染作为移动平台上的默认路径（正向渲染仍可作为可选功能使用）。

• 更广泛地使用GBuffer和深度数据。

• 移动端支持屏幕空间环境光遮蔽（SSAO）、屏幕空间反射（SSR）、延迟贴花、接触阴影和更高质量的水体渲染。

在虚幻引擎5.8中，我们还在目标材质和全局着色器通道中引入了半精度（FP16）着色器的用法，在保持视觉质量的同时提高了性能。

这些改进共同提升了高端移动硬件上的视觉保真度与可扩展性，同时在保证性能的前提下，为团队调整和优化画质等级提供了更大的余地。

Android平台支持

使用虚幻引擎5.8，我们针对Android平台进行了定向改进，重点提升了输入支持和迭代速度。

虚幻引擎5.8具备以下新特征：

• 已改进控制器映射支持。

• 使用Turnkey实现更简单的开发者工作站自动化配置。

这些更改提高了开发者的工作效率，并增强了平台的稳定性，使团队能够更加稳健地构建和测试Android项目。

预览平台

在虚幻引擎5.8中，我们提高了预览平台功能的视觉保真度，使编辑器中显示的视觉效果更接近目标硬件的外观和行为。

团队可以更早地发现视觉问题，并降低切换到设备进行迭代的成本。

有关此功能的更多信息，请参阅 Using Preview Platform

支持iOS和iPadOS的键盘和鼠标

在虚幻引擎5.8中，我们为iOS和iPadOS添加了完整的键盘和鼠标支持，让创作者和玩家能够使用标准的桌面输入设备与项目进行交互。 这使iPad和iOS的输入行为更接近macOS的表现，从而提升在开发、测试以及需要键盘和鼠标的Gameplay场景中的可用性。

在iOS和iPadOS上运行的项目现在可以在适当情况下，以保持一致、类似于桌面端的方式进行交互，从而减少在面向苹果生态系统时的跨平台适配摩擦。

适用于iOS和Android的手势事件（实验性）

虚幻引擎5.8版本中，我们引入了一个实验性的手势事件系统，该系统可连接iOS和Android上的原生手势识别器，并将其事件直接呈现给引擎。 捏合、滑动、旋转和拖拽等手势现在能够以与原生应用相同的精度、时序以及开始/改变/ 结束状态转换来识别，从而移除各平台的触摸处理代码，并为开发者提供在移动端驱动触控交互的一致方法。

iOS应用程序扩展

在虚幻引擎5.8中，我们通过新的.uappex控制文件，新增了一流的iOS应用程序扩展支持。 项目作者现在可以在其UE项目中声明诸如通知服务或背景资产之类的扩展，并且UnrealBuildTool会自动生成相应的Xcode应用程序扩展目标——无需在生成后手动编辑Xcode。

Unreal Engine Remote

Unreal Engine Remote是一个配套应用程序，让开发者无需编译或部署到物理设备即可预览和测试移动输入。 5.8版将应用程序扩展到Android（以前仅支持iOS），并将流媒体后端切换到Pixel Streaming 2，因此来自虚幻引擎5的实时编辑器内游玩会话或来自 Unreal Editor Fortnite特别版的移动预览会话可以流送到移动设备，从而在设备上镜像游戏体验并实时报告触摸和手势输入。

这意味着团队可以：

• 直接从预览会话中验证移动输入行为。

• 无需完整的设备编译即可迭代触摸控制。

• 在iOS和Android上，使用同一个应用程序，在虚幻引擎5和UEFN工作流之间进行测试。

UE Remote缩短了移动开发周期，让开发者能够快速、准确地了解输入在移动硬件上的体验，而无需在设备上反复部署。

有关此功能的更多信息，请参阅Using Unreal Engine Remote with Remote Session。

Steam帧支持（实验性）

我们与Valve合作，为其下一代XR平台部署了实验性支持：https://store.steampowered.com/sale/steamframe

bPackageForOpenXRImmersive是一个新设置，在VR模板中的默认值为true。

立体图层底衬

在虚幻引擎5.8中，OpenXR立体图层现在可以在主场景后面绘制。 这开启了XR效果，这些效果过去需要修改引擎或供应商专用插件才能实现。

在虚幻引擎5.8之前，虚幻引擎的OpenXR支持总是将立体图层绘制在投影图层（渲染的虚幻世界）之上，并且面部锁定图层总是位于世界锁定图层之上。 这个固定的顺序导致真正的“底衬”（即出现在环境后方的图层）无法开箱即用，尽管OpenXR规范本身只接受一个有序的图层列表，并未规定此类限制。

这一更改将固定顺序替换为由图层优先级驱动的顺序，与OpenXR的工作方式相匹配。 新增了两个新设置：

• xr.OpenXRProjectionLayerPriority（默认值 = 0）。 投影层的优先级。 任何优先级较低的立体图层都会在其后面绘制；任何优先级较高的立体图层都会在其前面绘制，与之前一样。

• xr.OpenXRSortFaceLockedLayersAboveOtherLayers（默认关闭）— 启用时，面部锁定图层始终绘制在其他所有图层之上，无论优先级如何。 这与之前的行为一致。

为了恢复虚幻引擎5.8之前的顺序，请将xr.OpenXRSortFaceLockedLayersAboveOtherLayers=1设置为1，并将xr.OpenXRProjectionLayerPriority设置为一个低于项目中所有立体图层优先级的值（例如，最小的32位整数-2147483648）。 现有项目仍可正常运行，无需更改。

有关详细信息，请参阅GitHub变更列表（需要关联账户）：https://github.com/EpicGames/UnrealEngine/commit/83641b6ac8b243d9858f54bafe1937f0accb4b6f

有关此功能的更多信息，请参阅OpenXR立体图层。

PICO控制器OpenXR插件

PICO控制器插件增加了对PICO的OpenXR交互配置文件XR_BD_controller_interaction和XR_BD_ultra_controller_interaction的支持。

插件在VR模板中默认启用，并且已为输入映射上下文配置了PICO控制器绑定。

iOS着色器模型6（实验性）

在虚幻引擎5.8中，我们为iOS添加了实验性的着色器模型6（SM6）支持，集成了苹果的Metal着色器转换器库，以解锁Apple Silicon上的高级GPU功能。

虚幻引擎5.8具备以下新特征：

• 新增专用的iOS SM6着色器平台变体，与现有的Metal路径并行提供

• 波内联函数（SIMD组操作），用于更高效的GPU计算算法

• 原生16位（FP16）着色器类型，以提高Apple Silicon上的ALU吞吐量

支持A15及更新的Apple Silicon，并作为实验性功能发布，同时保留现有的Metal渲染路径，以覆盖更广泛的设备。 针对受SM6限制的渲染功能（如改进的延迟渲染技术和更高质量的计算路径）的验证工作正在进行中，并将在后续版本中推出。

内容管线

UI重构 - 交换导入对话框UI

Interchange框架具有高度可定制性，因此用于配置Interchange和导入数据的窗口对话框选项非常多。

即将发布的版本以简化UI为目标。 在虚幻引擎5.8 中，我们 重新分组并重命名了 所有与资产类型转换相关的选项，以提高清晰度，同时，材质导入选项能够更清晰地控制是创建新材质还是使用现有材质。

有关此功能的更多信息，请参阅Interchange框架。

FBX导入性能

尽管glTF和USD的使用量不断增加，但FBX仍然是虚幻引擎中导入3D模型的主要数据格式。 为了改善这种格式的用户体验，我们引入了一个替代库。

在虚幻引擎5.8 中，我们进行了稳定性改进，以支持uFBX库（实验性）；它显著缩短了导入时间，很适用于包含大量网格体的大型.fbx文件。 多核CPU用户也会注意到包含大量网格体的文件的性能有所提升。

为与USD保持一致，在将文件导入关卡时，虚幻现在将保留.fbx文件的节点可见性，并将其应用于“在游戏中隐藏”属性。

USD资产预生成

USD场景通常由多个引用的USD文件递归组成。 当前的USD Interchange导入工作流会独立处理这些合成，导致导入扁平化并造成资产数据出现不必要的重复。

新的USD预生成框架引入了一个强大的系统，用于发现、跟踪和持久化引用的USD资产及其对应的虚幻引擎表示之间的关系。

此功能在虚幻引擎5.8中为实验性功能。 主要优点包括：

• 减少了资产重复

• 合成和资产感知处理

• 粒度处理

• 可配置框架

使用Interchange导入USD

USD是一种用途广泛的场景描述文件格式，在3D行业的采用率日益增长。

在虚幻引擎5.5中，我们将USD添加到了Interchange框架支持的文件格式列表中。 内容创建者现在可以对导入过程进行更多控制，可以为USD文件的资产导入添加自定义的处理步骤，类似于FBX等其他格式已有的Interchange功能。

在虚幻引擎5.8 中，Interchange的USD支持在资产导入中已达到生产就绪状态，但在关卡导入方面仍为实验性功能。 添加了对以下内容的支持：

• 模式处理程序的排序；加载USD文件时使用的模式处理程序的有序列表已公开并可进行编辑。

• 支持自定义模式转换器；USD转换器可以通过代码扩展以支持自定义模式。

• 一种添加新渲染上下文的机制。

• Nanite构建设置模式。

• 所有Groom属性。

• 折叠（与旧版USD导入保持一致）。

• Chaos布料

编辑器

编辑器小工具系统

在虚幻引擎5.8版本中，我们引入了一个新的编辑器小工具系统，旨在为整个编辑器提供更一致、更灵活的交互体验。 新系统基于交互式工具框架，多个旧版小工具实现整合到统一框架中，并在各类视口和工具之间共享使用。 这种统一提高了可靠性、交互一致性和可扩展性，便于开发人员在编辑器内构建工具。

重新设计的控件还包括一系列视觉和可用性改进，这些改进的灵感来源于美术师和关卡设计师所熟悉的工具（如Maya和Blender）的工作流程。 新系统改进了命中目标，提供了更清晰的视觉反馈、可自定义的交互预设和增强的精确控制，从而为操作Actor和资产提供了更快、更可预测的工作流程。

有关使用此功能的更多信息，请参阅变换Actor。

视觉和交互改进

• 优化的小工具设计：更薄的视觉轮廓和改进的命中目标，实现更精确的选择和交互。

• 改进悬停和交互反馈：在悬停或与轴和平面交互时，高亮显示清晰可见。

• 平面控制柄重新定位：平面移动轴被移至更远离中心的位置，从而提升可操作性并减少误选的情况。

• 扩展屏幕空间移动控制柄：扩大中心移动方块，使屏幕空间平移操作更加便捷。

• 改进轴可见性：轴在交互过程中暂时隐藏，以提高视觉清晰度。

• 改进缩放行为：现在，小工具在所有视角下都能更可靠地运行，从而实现更可预测的缩放交互。

精度与移动反馈

• 数字增量覆层：实时覆层在交互过程中显示移动、旋转或缩放增量。

• 增量线指示器：通过可视化线条显示物体相对于原始位置的移动距离。

• 旋转增量线：旋转交互会显示一条视觉增量线，类似于Blender，从而提高从更远距离旋转时的精度。

对齐和交互功能增强

• 对齐状态指示器：现在，小工具中心图标会直观地指示对齐功能何时启用。

• 临时对齐控制：按住修改键可快速切换位置、旋转、缩放或表面对齐。

• 视口边界交互：即使光标移出视口边界，也能继续操作Actor。

自定义和工作流程预设

• 交互预设：从多种交互样式中选择：

  • 默认虚幻引擎交互

  • 经典虚幻交互

  • Maya风格交互

• 可自定义的小工具行为：提高了团队的灵活性，支持他们根据首选工作流程配置交互。

精度控制

• 精度模式：暂时减慢变换速度以实现精细调整。

• 微调模式：增量调整平移、旋转或缩放，以进行可控编辑。

预览场景改进

虚幻引擎5.8版扩展了预览场景系统，增加了新的自定义功能和工作流程改进，以优化资产编辑器。 这些更新让用户能够更好地控制资产在预览时的呈现方式，从而直接在编辑器中更轻松地评估材质、网格体和光照条件。

自定义增强

• 自定义地板网格体支持：在预览场景中配置自定义地板网格体，以更好地匹配资产的使用环境。

• 自定义地板材质：将自定义材质应用于预览地板，以便改善查看资产时的上下文。

工作流程改进

• 布局改进：配置文件管理已移至选项卡顶部，访问更方便。

• 预览配置文件切换：使用键盘快捷键快速切换高级预览场景配置文件，让用户在评估资产时能够快速切换光照和环境设置。

材质预览编辑器改进

在虚幻引擎5.8中，我们对材质预览编辑器引入了多项改进，以支持更快的视觉开发和更灵活的预览工作流程。 这些更新使用户能够通过熟悉的预览网格更方便地评估材质，并在预览环境中直接快速测试资源。

预览功能增强

• 着色球预览网格体：着色球现在可作为原生预览网格体选项使用，为你提供一个熟悉的表面，用于评估材质和光照响应。

工作流程改进

• 拖放资产支持：你现在可以直接将资产从内容浏览器拖放到预览窗口中，从而更快地测试网格体和材质。

• 自定义网格体上的材质插槽：现在，当选择了自定义预览网格体时，可将材质应用于特定插槽。

快捷方式管理器

虚幻引擎5.8引入了全新的快捷方式管理器体验，让用户能够更快、更轻松地查找、管理和自定义编辑器按键绑定。 更新后的界面提供了改进的搜索功能、更清晰的命令显示，管理快捷配置的工具也更加精简。

更新后的快捷方式管理器拥有现代化UI，与虚幻引擎当前的编辑器样式保持一致，并提供增强的搜索工具，可快速定位已映射或未映射的命令，从而帮助开发者和美术师更高效地定制工作流程。

界面和易用性优化

• 视觉UI更新：更新了界面样式，以匹配现代虚幻编辑器的深色主题。

• 独立窗口：键盘快捷键现在拥有一个独立窗口，布局更紧凑。

• 更简洁的布局：减少了内联工具提示文本，提高了可读性，并使命令描述更清晰。

• 聚焦快捷方式搜索：搜索现在专门针对键盘快捷键，让用户更容易通过操作或命令名称找到命令，而不会出现不相关的结果。

增强搜索和发现功能

• 快捷键搜索：快速查找映射到特定按键组合的命令（例如，搜索Ctrl + S会显示绑定到该快捷方式的所有命令）。

• 按键绑定搜索按钮：专用选项，可通过按下按键组合直接搜索，显示所有已映射的命令。

• 高级搜索语法：可通过筛选结果查找特定状态（例如未绑定的命令），帮助识别可用于自定义工作流程的优化空间。

配置和工作流程

• 改进导入和导出：精简工具，用于在不同机器或团队之间共享和传输快捷方式配置。

• 更快的按键绑定管理：提高了命令和绑定的可发现性，帮助用户快速自定义编辑器体验。

编辑器偏好设置改进

在虚幻引擎5.8中，我们对编辑器偏好设置系统进行了更新，以提高一致性、可发现性和易用性。 编辑器偏好设置、项目设置和插件设置现在拥有更加统一的视觉样式和布局，使整个编辑器的配置更加直观易用。

对搜索、键盘快捷键和重置功能的额外改进，支持用户更快地找到并管理所需的设置。

界面和导航优化

• 统一设置样式：编辑器偏好设置、项目设置和插件设置现在共享一致的视觉设计和布局。

• 默认所有设置视图：设置现在默认以“所有设置”类别打开，以方便查找。

• 类别范围搜索：用户可以通过选择特定类别进行搜索，从而更轻松地缩小搜索结果范围。

搜索和发现功能增强

• CVar在搜索中的可见性：可轻松识别某项偏好设置是否由控制台变量（CVar）控制或受到其影响。

工作流程改进

• 键盘快捷方式访问：使用专用热键快速打开编辑器偏好设置、项目设置和键盘快捷方式。

• 重置为默认值：现在大多数设置都可以轻松恢复为默认值，方便进行功能试验，并在修改配置后快速还原。

正交视口改进

在虚幻引擎5.8中，我们对正交视口进行了一些改进，旨在提高清晰度和可用性，以便在顶视图、侧视图和前视图中工作时更加高效。 这些更新减少了视觉干扰，并确保重要的编辑工具在交互过程中保持清晰可见。

有关此功能的更多信息，请参阅正交摄像机。

视觉清晰度改进

• 改进打光视图渲染：减少了正交视图中大气雾的干扰，从而实现更清晰、更可预测的光照效果。

• 降低网格密度：正交网格已缩放，以减少视觉噪点和杂乱感，提高场景可读性。

交互改进

• 小工具在顶部渲染：变换小工具现在渲染在所选对象的上方，确保它们在编辑过程中保持可见且易于交互。

内容浏览器右键菜单

在虚幻引擎5.8中，我们对内容浏览器右键菜单进行了简化，旨在减少资产创建工作流程中的阻力。 这次改进的重点是降低菜单高度、更合理地整理资产类型，并让常用资产更容易找到，从而带来更整洁、更精简的右键菜单体验。

菜单结构优化

• 减少顶级类别：减少了右键菜单中的类别数量，以最大程度地降低高度并使菜单更易于浏览。

• 新增音频和动画子类别：为音频和动画添加了专用子类别，以更好地整理资产类型并避免列表过长。

• 新增数据分段：引入了数据类别，让数据导向的资产更容易识别和访问。

资产发现改进

• 常用分段中的材质实例：将材质实例添加到常用分段，以便更快地访问最常用的资产类型之一。

细节面板收藏夹

在虚幻引擎5.8中，我们扩展了细节面板收藏夹系统，支持更快、更轻松地导航和追踪重要属性。 这些更新可帮助用户快速找到常用设置，并识别复杂Actor和资产中的已修改属性。

收藏夹增强功能

• 收藏整个类别：用户现在可以收藏整个属性类别，从而更轻松地访问常用设置组，而无需收藏单个属性。

视觉反馈优化

• 类别分段筛选栏：该分段栏现在可以选择筛选细节面板，以显示收藏的类别或已修改的属性。你可以在细节面板的设置下拉菜单中启用这些设置。

工作流程优势

• 更快的属性导航：这些改进可让用户更轻松地查找常用设置，并能快速识别细节面板中的已修改属性。

MCP服务器（实验性）

在虚幻引擎5.8中，我们带来了一个新的实验性MCP（模型上下文协议）插件供虚幻编辑器使用。 该插件允许代理式AI系统连接到虚幻编辑器。 这样，这些系统就能够理解引擎和项目，同时帮助用户构建资产或系统。

有关此功能的更多信息，请参阅Unreal MCP。

沙盒

沙盒提供了一个独立的工作空间，你可以在其中进行实验，而不会影响主项目。 打开沙盒，自由创建和编辑，仅保留你想要的内容

你不再需要为了尝试新功能而创建分支、将资产复制到WIP文件夹，或担心污染版本控制。

• 你可以创建沙盒并在其中工作，而不会影响项目内容。从专用浏览器中浏览、切换和查看沙盒中的变更

• 仅持久化你想在项目中保留的更改

• 导出沙盒与团队成员共享，或导入沙盒 以从对方离开的地方继续工作。

制片渲染管线

影片渲染图表（生产就绪）

影片渲染图表在虚幻引擎5.8版本中进入生产就绪状态。

基于图表的配置现在支持旧版预设中的所有主要功能。 用户可以继续使用基于预设的配置，但今后的新功能将仅支持图表。

有关使用此功能的更多信息，请参阅影片渲染图表。 

光源修改器

着眼于后期合成工作流程，光源修改器使美术师能够在影片渲染图表中按渲染层设置和重载光源Actor的属性值。 美术师可以使用相同的关卡和关卡序列隔离单个光源或光源组，并使用不同的强度、颜色和/或任何类型光源的自定义属性值渲染镜头。

收集节点上的新光源Actor类型条件使光源分组以便按渲染层修改变得既简单又方便。 属性也可以转换为图表变量，并在快速渲染和影片渲染队列窗口中作为重载项公开。

累加景深

与实时性能相关的景深渲染考量，可能会限制在强调该效果的镜头中的视觉质量。 为了实现更具“电影感”的景深效果，美术师必须切换到路径追踪器，但这会显著增加渲染时间成本，并且需要在所有镜头中统一使用以保证一致性，即使是那些并不依赖景深的镜头也不例外。 理想情况下，可以提供一个选项，在性能与质量之间实现两者兼得的最佳平衡。

累积景深是一项新功能，它使用影片渲染图表累积来自多个光圈视点的延迟渲染，从而渲染景深。 这大大减少了由于缺少视差而产生的伪影，同时保留了延迟渲染的外观开发。 美术师可以在默认景深无法达到预期视觉效果时使用它，并避免在不需要景深的镜头上产生开销。

图表中的nDisplay渲染

虽然nDisplay部署可以（而且通常会）实时运行，但使用影片渲染队列来渲染集群在某些场景下非常有用，例如预渲染播放以及WIP内容审查。 在虚幻引擎5.8版本中，我们将nDisplay与影片渲染图表集成，以更好地支持可扩展渲染设置。 UE 5.8功能集包括：

• 支持集合、修改器和渲染层。

• 支持延迟渲染器和路径追踪器。

• 控制Sequencer中的DCRA，或在图表配置中使用重载。

• 用于DCRA、节点、视口等nDisplay概念的内置文件命名标记。

• 支持立体渲染。

ICVFX摄像机支持将在未来版本更新中推出。

有关使用此功能的更多信息，请参阅nDisplay概述。

新建队列窗口 - 基本配置

在虚幻引擎5.8中，我们引入了全新的简化版队列窗口，提供基础配置，可在面板中直接为单图层渲染设置名称、分辨率和输出位置等常用属性。 美术师可以在延迟渲染器和路径追踪器之间进行选择，并更改输出类型，无需打开另一个窗口或保存资产。

默认值可以自定义并保存，以便队列始终以正确且所需的设置打开。 基本配置的当前状态也可以保存为图表配置，用作更复杂渲染设置的起点。

虚拟制片

动捕管理器（Beta测试版）

在虚幻引擎5.8中，我们改进了动捕管理器，具体如下：

• 自动摄像机：生成并控制程序化摄像机，摄像机可动态跟随并拍摄动作。

• 用户可扩展性：用户现在可以创建自己的自定义工作流程UI。

• 专用面部动画预览：快速检查面部动画，无需移动视口摄像机。

• 改进了重定向调整。

• 捕获管理器视频摄取支持：动捕管理器现在可以将面部动画视频与其余表演捕捉会话数据纳入同一管线。

• 音频录制可配置性：与镜头试拍录制器相同，定义每个录制轨道的音频设备和通道选择。

• Live Link中心设备集成：从动捕管理器控制中心录制。

Composure（Beta测试版）

新的Composure在虚幻引擎5.8版本中进入Beta测试阶段。 针对实时和后期可视化场景引入多项改进，包括：

• 为合成Actor和引用的摄影机Actor提供完整的Sequencer支持（包括可生成对象）。

• 轻量级平面反射和单一光源阴影层带来了更快的性能选择。

• 通道现在可以在任何图层上配置（不仅仅是板层），并且有几个新增和改进的通道：

  • 模糊（Blur）

  • 膨胀

  • 遮罩

  • 后期处理材质

  • 首先是变换（Transform）

  • 半透明度

• Composure面板用户体验改进：

  • 同步Actor选择。

  • 管理合成网格体材质。

  • 将特定组件指定为合成网格体和/或阴影/反射捕获器内容。

  • 直接从Composure启动媒体捕获。

  • 使用当前板创建天空球体Actor的便捷选项。

• 色彩分级：通道与编辑器的色彩分级面板集成。

Composure键控器

高质量键控是所有合成工具集的基本功能，在虚幻引擎5.8中，我们在几个关键方面扩展了Composure的选项：

• 在选择键控颜色时，无需在编辑器中切换上下文即可查看媒体纹理的预览。

• 在Composure面板中单击，从实时内容中获取清洁底板纹理，轻松将其保存为资产，并且自动将其设置到合成Actor中。

• 使用亮度键控器通道代替或补充颜色键控器通道。

• 将Ultimatte与Composure结合使用，通过配置渲染管线的定制通道，确保正确的颜色精度。

• 使用新的膨胀通道调整边缘。

在视口中显示Alpha

使用新的视口可视化选项，直接在编辑器中检查红色、绿色、蓝色或Alpha通道。 通道菜单新增额外选项，可将其固定到视口菜单以便快速访问，并以棋盘格形式显示Alpha。

nDisplay自动曝光

虚幻引擎项目通常使用自动曝光，自动曝光会采样场景缓冲区并计算平均亮度直方图，从而动态调整曝光值。 迄今为止，nDisplay仍需要手动曝光值来确保跨视口的连续性。 在虚幻引擎5.8中，我们为nDisplay引入了自动曝光支持。

测量可以使用整个nDisplay DCRA，也可以使用适用于集群其余部分的特定节点或视口。 你还可以从自动曝光中排除项目。

Linux Rivermax

除Windows以外，虚幻引擎5.8中的Nvidia Rivermax插件现在还支持Linux操作系统，并具备经验证的nDisplay ICVFX功能。

Live Link中心——设备框架

对于需要在表演捕捉会话期间使用多台录制设备的团队，Live Link中心现在提供一个设备框架，支持通过IP管理动捕摄影棚内的所有设备。 现在，你可以集中监控所有Live Link数据、虚幻引擎编辑器客户端并控制录制设备。

Live Link中心支持多种设备：

• iOS版和Android版Live Link Face

• AJA视频设备

• 声音设备音频录制器

• OBS屏幕录制器

Optitrack和Vicon等第三方动捕硬件和软件供应商将为虚幻引擎5.8提供插件更新。

你的虚幻引擎客户端（运行动捕管理器或镜头试拍录制器）可以将场记板名称和镜头试拍编号推送到Live Link中心和连接的所有设备，并控制录制的开始和停止。 将你需要的场记板和镜头试拍输入同一位置，在整个动捕摄影棚中保持一致。

Live Link中心——时间码和时间步控制

用户现在可以使用Live Link中心的媒体描述文件，远程设置所有已连接虚幻引擎客户端的时间码和时间步，在表演捕捉舞台设置和项目中保持录制数据的一致性。

• 支持Live Link时间码和系统时间码提供器。

• 支持时间码自定义时间步和Live Link自定义时间步。

Live Link中心——视频监控

Live Link中心现在使用虚幻引擎的媒体描述文件来查看和控制视频数据，以用于动画解算和参考监控。 用户可以使用新的RTSP媒体源，以及现有的AJA、BlackMagic和NDI媒体源，在表演捕捉会话期间监控多个视频源，包括从Android和iOS上的Live Link Face应用进行流送。

MetaHuman视频Live Link源现在可以将媒体描述文件中的视频源用作面部动画数据，使更多的摄像机和捕捉设备可用于面部捕捉。

编辑器工具命名标记

现在，用户可以创建编辑器工具命名标记，它们可以访问以前运行时命名标记无法访问的编辑器功能。

• 直接在命名标记蓝图中调用编辑器工具函数。

• 在评估标记时执行Python节点，并从你的数据库或外部进程中检索标记值。

CAT模式中的集成时间轴模板编辑器

现在可以直接在模式编辑器中制作时间轴模板。 过场动画美术师不需要再反复手动构建相同的序列布局。 模式可以在未来的模式时间轴中作为子序列被引用，让你能够为摄像机、特效、光照等创建可复用模板的嵌套层级。

• 设计一次模式模板，即可在每个组装中重复使用。

• 在模式编辑器中创建可视化模板结构，无需离开过场动画组装工具。

• 指定从该模式创建的每个组装中应包含的轨道、文件夹、可生成对象和子序列。

• 将模式作为子序列嵌套，以可管理模块的形式创建复杂的层级结构。

在镜头试拍录制期间引用可生成对象并将其设为父级

Actor现在可以通过镜头试拍录制保持对可生成对象的引用。 以可生成对象为父级的Actor在整个录制过程中将保持该父子关系，并在结果中通过附加轨道正确录制。 无需再完全依赖可控制对象或创建自定义工具来替换录制开始时损坏的可生成对象引用。

• 在整个设置和录制过程中安全地引用可生成对象。

• 重新录制同一Actor以使其可生成，而不覆盖现有录制。

• 使用世界大纲视图将可生成对象设为父级，并在录制过程中保持该父子关系。

VCam附加浏览器和约束

虚拟摄像机现在拥有一个专用的父子层级与平台设置浏览器。

• 在VCam UI中浏览所有可附加的Actor和组件。

• 无需离开VCam，即可将摄像机附加到目标上或从目标上卸下来。

• 按关键Actor类型筛选，或仅筛选你附近的Actor。

VCam按轴附着

VCam现在通过动画约束与其父级关联，让你能够选择继承或忽略哪些轴，从而实现更精细的控制。Composure面板用户体验改进

媒体

平铺Mipmap视频（实验性）

随着EXR播放对图块和Mip的支持，我们实现了在复杂的显示设置上进行高分辨率播放。 在虚幻引擎5.8中，为了给用户提供更平衡的播放体验，我们新增了TMV，这是一种支持图块与MIP贴图并具备压缩能力的视频容器格式。 这将解决EXR文件过大的开销以及高性能视频播放的带宽要求。

这针对的是ICVFX、现场活动以及任何需要为游戏引擎提供可靠视频格式的用户。

TMV可帮助用户实现以下功能：

• 同类最佳的引擎内视频播放（只从磁盘流送所需的像素，而不是解码整个视频帧）

• 流畅的拖动播放（性能可与Apple ProRes拖动播放相媲美）

• 实现高图像质量，并同时保持存储占用合理（无损与有损压缩算法）

• 支持高位深度HDR编码

• 支持低延迟，仅显示视野范围内所需的内容。 图块可以根据请求进行流送加载和卸载。

视频转码器（实验性）

专业视频编辑工具通常会将传入的视频资产转码为通用的优化视频格式，以增强拖动播放和编辑功能。 在虚幻引擎5.8中，我们添加了一个实验性视频转码工具，可以将行业内大多数可用的输入格式转换为我们全新的TMV（平铺Mipmap视频）视频容器。

转码后，视频资产就可以像其他格式一样在引擎中播放。 主要区别在于，TMV经过优化可在游戏引擎和3D渲染环境中实现最佳播放效果。

面向需要将视频转码为EXR或TMV容器（无论是否包含图块与mip）的用户。

在这个版本中，我们新增了以下功能：

• 任务管理（添加、复制或删除任务）

• 它可以作为命令行（CLI）执行任务

• 将工具配置导出为json格式

• 实时转码进度预览

• 支持图像序列（包括EXR）和视频文件

• 图块和MIP贴图自定义

• 颜色管理和重载

• 质量设置

媒体查看器（测试版）

动画师常常需要根据现有的参考画面来调整动画。 在5.6中，我们添加了将媒体（图像、媒体纹理、视频文件、实时视口）停靠在动画工作位置旁边的功能。

采用水平或垂直配置的两种AB库能帮助用户对比两组资产。 缩放和平移功能按钮可用于进一步对齐放置的内容。 书签功能支持通过快捷键快速调用资产配置。 在虚幻引擎5.8中，媒体查看器插件更接近生产就绪状态，它包含以下工作流程和可用性改进：

• 改进了访问Sequencer媒体纹理的工作流程。

• 水平/垂直图像库翻转。

• 缩放级别可调的筛选模式，并带有像素网格显示。

• TMV（平铺Mipmap视频）支持。

有关此功能的更多信息，请参阅媒体查看器。

模拟和视觉特效处理

Chaos破坏系统

Chaos破坏系统提供了一套强大的工具，可实时实现电影级的破坏效果，兼具高视觉保真度和强大的性能优化能力。 虚幻引擎5.8的更新包括：

编辑器

• 现在，创建资产时可使用默认数据流模板。

• 现在，新资产的缩略图上会显示一个图标，表明其关联了数据流。

• 新增几何体集合渲染类型的渲染设置。

组件

• 新增为每次变换设置线性阻尼和角阻尼的功能。

• 新增可查询当前变换的蓝图函数：

  • 获取当前变换

  • 从索引获取当前变换

• 修复了Niagara破坏数据接口中不正确的索引，该问题导致部分粒子在原点生成。

• 修复了在几何体集合组件上设置碰撞响应的问题。

• 为几何体集合添加了对陀螺仪扭矩选项的支持。

• 修复了从游戏线程同步时，GT粒子速度未正确设置的问题。

• 更新了角色移动，以便将骨骼名称正确传递给获取线性速度的函数。

• 修复了使用睡眠时移除或中断时移除时，追踪在部分簇上无法正常工作的问题。

场

• 修复了场处理部分簇时可能发生崩溃的问题。

有关使用此功能的更多信息，请参阅Chaos破坏系统。

Chaos数据流编辑器

数据流是虚幻引擎中一个基于节点的系统，可用于程序化生成基于物理的资产。 它被广泛用于布料、破坏、毛发、肉体和MetaHuman设置等工作流程。 虚幻引擎5.8的更新包括：

• 运行时图表求值。

• 优化了用户界面和用户体验（更具交互性的工具、小工具等）。

• 骨骼网格体制作。

  • 改进了几何体工具（合并）。

  • 更完善的约束创建工具套件。

• 图表内缓存。

Chaos可视调试器

Chaos可视调试器（CVD）让虚幻引擎用户能够有效观察和调试物理模拟，既可以在虚幻编辑器中直接进行，也可以通过独立的CVD实例进行。 虚幻引擎5.8的更新包括：

• 摄像机追踪系统。

• 几何体可视化面板。

• 支持多选。

• 三角网格复杂度视图。

Chaos核心

我们正在对虚幻引擎的Chaos物理系统进行基础性改进，以支持响应更灵敏、更具可扩展性的模拟工作流程。 虚幻引擎5.8的更新包括：

• 改进了线程安全岛屿生成。

• 可以更灵活地控制对象敏感度与岛屿休眠。

• 通过空间或颜色分离实现更好的岛内并行化。

• 受保护的解算器API和新的执行模型。

• 持续推进单块物理线程移除工作，转向作业图。

• 扩展的元宇宙就绪过滤模型：

  • 64位通道。

  • 通道遮罩对比 单通道选择。

  • 过滤器扩展至支持超过64通道。

• 数据流中的骨骼网格体制作

• 在刚体和可变形解算器中实现更好的缩放和限制。

  • 本地空间模拟。

  • 速度限制。

  • 移除按形状缩放的ImplicitObjectScaled。

• 用于数据流的Chaos++解算器节点，用于验证世界求解器外部早期API。

Chaos缓存

缓存框架项目致力于扩展现有系统，以便为基于Chaos物理的布料、流体、破坏和肉体等高效地存储和播放仿真数据。 虚幻引擎5.8的更新包括：

• Sequencer中的按组件缓存。

  • 支持编辑器端烘焙和运行时播放。

• 使用Chaos缓存资产作为元资产，指向更相关的优化格式。

• 新增用于缓存版本控制、修剪和失效的工具。

• 过场动画工作流程验证。

  • Sequencer中的布料静止姿势静止姿势。

Chaos毛发

虚幻引擎5.8中针对Chaos毛发的更新包括：

• 扩展了对绘制属性、蒙皮权重和引导交换的支持。

• Nanite兼容渲染和模拟。

• 发片生成到骨骼网格体。

• Groom编辑工具（修剪/卷曲）。

• 原型发束渲染。

Chaos Flesh

该项目致力于将布料和肉体的Chaos解算器统一到一个可变形模拟框架中。 虚幻引擎5.8的更新包括：

• 将布料和肉体解算器合并到一个可变形核心中。

• 启用了图层（皮肤、肌肉、服装）之间的程序化交互。

• 通过共享内存和解算器逻辑提升性能。

• 更新了数据流节点，以使用新的数据流渲染系统。

Chaos布料

在虚幻引擎5.8中，Chaos布料已经可用于生产。 更新包括：

• 支持与CLO/Marvelous Designer的非破坏性更新及双向编辑。

  • 将USD约束和布料属性导入虚幻引擎。

  • 保留面板结构、弹簧和模拟元数据。

• 支持数据流中的模拟播放和重新编辑。

• 启用了图层（皮肤、肌肉、服装）之间的程序化交互。

• 通过共享内存和解算器逻辑提升性能。

• 布料交互件资产数据，有助于管理蓝图中的属性组设置。

• 在全速缩放模拟中增加了虚拟力。

Chaos模块化载具

模块化载具系统让用户能够使用动态场景图组件实时构建载具，而不是依赖固定的骨骼网格体。 采用客户端预测和服务器权威物理设计，支持灵活的构造。 该系统使创作者能够在虚幻引擎中使用模块化部件制作传统或非传统的载具。

• 新增使用骨骼网格体构造载具的支持，让用户能够使用相同的框架轻松创建简单的载具。

• 新增载具和地面之间的双向交互。

有关此功能的更多信息，请参阅Chaos模块化载具。

平台SDK升级

• Windows

  • 推荐Visual Studio：2026

  • 最低Visual Studio版本：2022 v17.14或更高版本

  • 推荐MSVC：14.50

  • 最低MSVC版本：14.38

  • 默认Windows SDK：10.0.26100.0

  • Windows SDK最低版本：10.0.22621.0

  • LLVM clang

    • 最低：18.1.8

    • 推荐：20.1.8

  • Intel OneAPI

    • 最低：2026.0.0

    • 推荐：2026.0.0

  • 适用于VS 2026的.NET 10.0

  • 其他注意事项

    • 使用Visual Studio 2022进行任天堂开发，并使用v26.1.102以下的AGDE。

• 构建农场编译时面向的IDE版本

  • Visual Studio 2022 17.14, 14.44.35207工具链和Windows 10 SDK (10.0.22621.0)

  • Xcode 16.1

• GDK

  • GDK：2026年4月

  • 最新恢复版本

  • 支持的IDE：Visual Studio 2022和2026

  • Windows SDK最低版本：10.0.22621.0

  • 其他注意事项

    • 2026年4月之前的GDK请使用Visual Studio 2022。

• Linux

  • 原生Linux开发

  • 推荐操作系统：Ubuntu 22.04、Rocky Linux 8或更高版本、Redhat Linux 8或更高版本

  • 编译器：clang 20.1.8

  • 交叉编译工具链：基于v26 clang-20.1.8

• macOS

  • 推荐操作系统：最新的macOS Sonoma 14

  • 最低操作系统：macOS Sonoma 14.0

  • 推荐Xcode：15.4或更高版本

  • 最低的Xcode：15.2

  • 支持的macOS SDK：14及更高版本

  • 注意：由于使用最新版本时在编译和链接方面存在一些问题，因此支持的Xcode版本已从UE 5.6降级。

• iOS/tvOS/iPadOS/visionOS

  • 推荐操作系统：最新的macOS Sequoia 15

  • 最低操作系统：macOS Sonoma 14.5

  • 推荐Xcode：26.1.1

  • 最低Xcode版本：26.0

  • 支持的目标SDK版本：17或更高版本

  • 支持的iOS SDK版本：17或更高版本

  • 支持的iPadOS SDK版本：17或更高版本

  • 支持的tvOS SDK版本：17或更高版本

  • 推荐搭载Xcode 26.1.1的visionOS 2.4

  • iOS图形API：Metal 2.4 - 3.1

  • 其他注意事项

    • Shader Model 6（SM6）需要iOS26+系统，以及Apple A17Pro或更高配置的设备。 此项支持目前为Beta测试版，暂不推荐应用到生产环境。

• Android

  • Android Studio Koala 2024.1.2补丁1（2024年9月17日）

  • Android NDK r27c

  • Android SDK

    • 推荐版本：SDK 35

    • 用于编译UE的最低版本：SDK 34

    • 用于发售的默认目标SDK：SDK 34

    • 最低安装SDK级别：SDK 26

    • 推荐AGDE：v26.1.102

    • 最低AGDE版本：v23.2.91

  • 编译工具：35.0.1

  • Java运行时：

    • OpenJDK 21.0.3 2024-04-16

    • OpenJDK运行时环境（构建21.0.3+-12282718-b509.11）

    • OpenJDK 64位服务器虚拟机（构建21.0.3+-12282718-b509.11，混合模式）

  • 其他注意事项

    • 虚幻引擎已更新为使用Gradle 8.7，我们使用的Android Gradle插件（AGP）版本也已更新为8.5.2。 如果你使用Android Studio进行调试，那么我们推荐使用Android Studio Koala。 Ladybug也可用，但不要从上述版本更新Gradle或AGP。

    • 选择NDK等级时，应该以android-26为目标，因为它支持Android 8.0以上版本。

• EOS

  • 1.19.1.2-53289219

• Steam

  • 1.64

• Switch

  • 默认SDK版本：21.4.2

  • 默认固件版本：21.2.0-1.0

  • 最低SDK版本：20.5.6

  • 最低固件版本：20.0.0-10.0

  • Nintendo文件包管理器：1.8.2

  • 支持的IDE：Visual Studio 2022

• Switch 2

  • 默认SDK版本：21.4.2

  • 默认固件版本：21.2.0-1.0

  • 最低SDK版本：20.5.6

  • 最低固件版本：20.0.0-10.0

  • Nintendo文件包管理器：1.8.2

  • 支持的IDE：Visual Studio 2022

• PS4

  • 默认Orbis SDK 12.508.031

  • 最低Orbis SDK 12.008.011

  • 系统软件13.508.001

  • 支持的IDE：Visual Studio 2022

• PS5

  • 默认Prospero SDK 13.00.00.35

  • 最低Prospero SDK 12.00.00.38

  • 系统软件13.20.00.06

  • 支持的IDE：Visual Studio 2022

• ARCore

  • 1.48

• ARKit

  • 4.0

• OpenXR

  • 1.1.46

  • 支持OpenXR 1.0和1.1运行时，两者均可在项目设置中禁用。

版本说明

AI/ML

New:

• Learning Agents: Remove firing OnAgentsAdded and OnAgentsRemoved if they are empty.

• LACombat: Split schemas into a separate map and make recordings filterable with tags.

Bug Fix:

• Learning Agents: Fix memory leak in LearningAgentsRecorder.

MCP

New:

• Added an assistant toolset for animation features.

Bug Fix:

• Fixed boolean type parsing issue with ECA Bridge.

Neural Network Engine (NNE)

New:

• Upgraded ONNX Runtime to 1.24.3 and DirectML to 1.15.4 in the NNERuntimeORT plugin.

• Upgraded the NNERuntimeIREE third-party compiler, runtime, and tools to IREE 3.11.0.

• Added per-model compiler flag settings for the NNERuntimeIREECpu runtime.

• Added.mlpackage import support to the NNERuntimeCoreML runtime.

• IREE runtime trace zones from NNERuntimeIREE are now captured by Unreal Insights in non-Shipping configurations.

Deprecated:

• Removed: Dropped the NPU execution interface from the NNERuntimeORTDml runtime.

Animation

New:

• Added accessors for Vector and Quaternion attribute types to SkeletalMeshComponent.

• Marked UAnimNotify as EditInlineNew.

• Added virtual Merge function to UAssetUserData.

• Made the Animation Curve Debugger Widget read-only per default.

• Added a remap (v, min_in, max_in, min_out, max_out) function to the Curve Expression plugin. This function remaps the input value such that its value within the in_min/max range is linearly mapped to the out_min/out_max range, much like the FMath::GetMappedRangeValueClamped C++ function.

Bug Fix:

• Fix infinite loop in rich curve feature point search function.

• Remove improper usage of FKeyHandle constructor Reduces unique key ID churn.

• Fix for PoseableMeshComponent for when Skeleton changes during its lifetime.

• Makes AnimationEditorPreviewScene and the EditableSkeleton (more) robust to the Skeleton being deleted.

• Fixed restoring of animation position and play state in montage and animation editors after undo/redo actions.

Deprecated:

• Cleaned deprecated methods from Animation.

Animating in Engine

New:

• Curve Editor

  • The Curve Editor's frame hotkey now zooms to your selected keys' range, or falls back to the selection/playback range when nothing is selected, matching Sequencer's framing behavior.

  • Copy/pasting curves now applies the source curve to every selected target with a matching name, not just the first match.

  • The tree view now has an Organize and Sort menu which has options to Expand/Collapse Nodes, Expand/Collapse Nodes and Descendants, Expand All Nodes, Collapse All Nodes, and Sort All Nodes.

  • Added Middle Mouse Button Adds Key setting to enable or disable adding a key with the middle mouse button.

  • Ctrl-mouse wheel and alt-right mouse button now zoom horizontally even when there's no curves selected.

  • The selection range start/end shortcut binding now shares Sequencer's binding so the behavior stays consistent across both.

  • Toolbar cleanup by removing the unused All Edits button and the 'Curves' label from the pulldown.

• Anim Details

  • Anim Details now shows an option to remove all keys in the right-click context menu of its properties.

  • Anim Details now groups Control Rig properties with identical names, regardless of their relation in the rig.

    • Control Rig Controls are now grouped per property name, ignoring their parent, while common Actor properties still show grouped per parent Actor Components as previously.

    • Groups now show the control name if multiple parents with identical name are multi-edited and "Multiple" only if controls of different short names are multi-edited.

    • Groups now show a tooltip listing up to 5 controls when multi edited.

• Added Blueprint functions Open Pose Library Tab and Close Pose Library Tab.

• Snapper settings are now saved as user preferences.

Bug Fix:

• Curve Editor

  • Normalized and Stacked views no longer collapse all keys to the bottom when the curve values are nearly identical.

  • Improved interaction by not changing curve selection if there's nothing to change and not transacting key drags if there's no movement.

  • The Normalized view now respects the Frame Output Padding setting instead of using a hardcoded 10% margin.

• The time offset filter now handles pre and post infinity extrapolation by wrapping around.

• Tween slider now responds to both its primary and secondary keyboard shortcuts.

• The Tween Slider no longer fails to show up if the mouse is too close to the left border of the viewport.

• The pose browser now maintains its configuration and doesn't rebuild each time a pose is selected.

• Anim Layers UI now follows add/remove/duplicate layers and undo/redo, regardless of whether controls are selected or not.

• Enums now show their keyed status in Anim Details.

• Changes to bool, float and int properties in Anim Details are now reflected in Sequencer.

• Selecting plain Location Controls in Anim Details now filters channel curves correctly.

• Control Rig and Sequencer: Fixed Control rigs recreated with "Recreate Control Rig with New Settings" reverting to default setting when entering PIE.

Character Customization

New:

• Added support for Chaos ClothAssetSKMClothingAsset.

• Renamed Passthrough nomenclature to Object. This new naming convention gives insights to the user when a UObject is created.

• Merged Texture and Passthrough Texture nodes.

• Added new Skeletal Mesh type and nodes. This new type allows users to work at Skeletal Mesh level without having to enumerate all Mesh Sections.

• Converted Add To Component SKM node to Modifier Skeletal Mesh Merge.

• Added Skeletal Mesh output pin to Skeletal Mesh Parameter node.

• Added the "Skeletal Mesh Modify" node.

• Removed one Game Thread tick when Updating. Updates now can take a minimum of two ticks.

• Added Asset User Data type and nodes.

• Added new UAssetUserData type and nodes.

• Added the "Mesh Transform with Bone" node to serve as an inlined version of the modifier node with the same name.

• Added the "Remove Mesh" node.

• Implemented Parallel Updates. Now MIPs and LODs and Initial Updates can be generated in parallel.

• Added support for Clothing in Skeletal Mesh parameters.

• Components now can have the same name.

• Added the option to taking the ownership of generated resources. Mutable will not modify or reuse them.

• Added Material Override pin to components.

• Added the "Skeletal Mesh Break" node.

• Added Passthrough Skeletal Mesh pin to Node Passthrough Skeletal Mesh Component.

• Added Passthrough Texture Parameter node.

• Added custom External Operations. Allows users to create new operations. Very experimental!

• Moved Modifier Skeletal Mesh Mesh LOD Pins to a Skeletal Mesh Make.

• Marked Transform in Mesh nodes as deprecated.

• Added an option to define the maximum UV layout size, in blocks, for the Mesh Section and Material Modify nodes. The size of runtime-generated textures is derived from the 'Max Layout Blocks' setting and the in-game size of the reference textures.

• Hidden compile properties when a CO is a Child.

• Removed Parameter Profiles.

• Removed Node Copy Mesh Section.

• Added support for SkinWeightProfiles in Skeletal Mesh Parameters.

• Removed CO States tab.

• Hidden Child Object properties when it is not the root.

• Removed selector list from Mesh Morph. Now it is a simple string.

• Optimized Skeletal Mesh merge operations.

• Added Skeletal Mesh Break node.

• Added NodeSwitch for Skeletal Mesh Objects.

• Added Skeletal Mesh Merge node.

• Added the "Skeletal Mesh Morph" node.

• Improved usability of the debugger by adding the option to color the tree of operations using the operation data type.

• Add Serialization Support for Material Params in LoadDescriptor.

• Optimized mutable runtime performance by transforming chains of conditional ASTOps into switches.

• Changed Group Type option names.

• Allowed Reroute Node to have multiple outputs.

• Refactored the Mutable system tick to reduce the time spent on game-thread.

• Improved mutable runtime performance by the removal of the "Task_Game_LockCache" task from the Customizable Object Instance update.

• Optimized Game Thread BuildOrCopyClothingData.

• Image layer operation optimizations.

• Added support for Skeletal Meshes with unlimited bone influences in Skeletal Mesh Parameters.

• Added support for Skeletal Mesh sockets in Skeletal Mesh Parameters.

• Improved the reporting of cyclical CO references.

• Moved all functionality of the Passthrough Mesh Component" node into the "Skeletal Mesh Component" node. Removed "Passthrough Mesh Component" node.

• Allow use of Skeletal Meshes without NeedsCPUAccess enabled in Skeletal Mesh Parameters.

• Real-time morph generation optimizations.

• Added support for PhysicsAssets in Skeletal Mesh Parameters.

• Remove LOD limiters CVars.

• Moved loading CO hierarchies from synchronous to asynchronous.

• Make FCustomizableObjectInstanceDescriptor Load/Save functions safer.

• Removed Share Projector Between LODs optimization.

• Added backward compatibility support to Customizable Object Macro libraries to update nodes within macros.

• Changed Break Skeletal Mesh node color.

• Removed Low Priority Textures.

• Removed Material references from Generated Textures in Texture Analyzer.

• Added colors to Performance Analyzer.

• Added 'Bone Pose Priority' property to object group nodes to resolve conflicts when merging meshes with different poses.

• Added the option to define the output prefix for the assets generated by the mutable Customizable Object Instance Baking operation.

Bug Fix:

• Fixed "Clip mesh with UV Mask" operation not loading the appropriate texture mask mip.

• Fixed an issue with MinQualityLODLevels where the streamer would request Skeletal Mesh LODs below the platform MinLOD setting.

• Fixed actor creating more components than it should.

• Fixed high video memory usage when generating a lot of meshes in the CustomizableObject editor.

• Fixed modifier nodes not being able to display the UVs of mesh section nodes that did not define at least one non-automatic tag.

• Hair Strands Mutable: Fixed check failure when trying to create a new UObject from the PostLoad of the "Groom Constant" node.

• Fixed OOM crash when moving a slider.

• Fixed modifier nodes missing the input "RequiredTags" input pin on node refresh.

• Fixed unable to save baked resources if they contain invalid characters.

• Fixed multiple cases where the messages produced by mutable did not get exposed in the "Stats" Customizable Object editor tab.

• Fixed "unable to remap pin" warning during the update of the "CONodeMeshMorphStackDefinition" backwards compatibility code execution.

• Fixed compilations not using the root CO compile options.

• Fixed multiple issues with Reshape nodes.

• Fixed wrong order of the Customizable Object versions array making a backwards compatibility related fix for a missing pin be performed after it was required.

• Fixed modifiers always applying when All Required + No Tags.

• Fixed bake operation not re-compiling the Customizable Object when the compiled data is outdated.

• Fixed an issue where Skeletal Mesh Component nodes added to child Customizable Objects were ignored.

• Fixed crash when the RunCode operation was aborted when the material parameter could not be found.

• Fix for automatic compilation in editor not picking up on changes from in a Customizable Object Macro Library. Now changes will be picked up on autocompilation and be represented in the output.

• Fixed PrepareUnrealCompression Game Thread check.

• Fixed ImagePixelFormat not being used in Bake.

• Fixed crash when validating Customizable Objects.

• Fixed Code Viewer stack overflow crash with large COs.

• Fixed a memory leak when converting Skeletal Meshes from Skeletal Mesh Parameters at runtime.

• Fixed ensure when registering to Movie Sequence Template actors using HairStrandsMutable.

• Fixed Customizable Object being GC during package splitter.

• Fixed an issue with Skeletal Mesh streaming where streamed LODs remained in memory until the Skeletal Mesh was destroyed.

• Fixed Material Switches losing its type.

• Fixed Extension Data not being applied when an Instance is already generated.

• Fixed crash if the PinType is None.

• Fixed modifier nodes not showing the custom tags explorer UI element.

• Fixed morph-related error messages not having the node context set in them.

• Fixed UVs changing precision when streaming.

• Fixed crash when failing to stream an Image.

• Fixed scaling issue with the Layout areas caused by the unrequired clamping of the layout areas when not really needed.

• Fixed crash when removing all vertices of a cloth section.

• Fixed cloth crash when streaming was enabled + using a Remove Mesh node.

• Fixed the "FCustomizableObjectMeshStreamIn" tasks leaks that caused the "FLiveInstance" and "FCustomizableObjectMeshStreamIn" objects to be wrongfully kept in memory.

• Fixed Callback check when Streaming in FCustomizableObjectMeshStreamIn.

• Fixed PSO check with grooms.

• Fixed crash when deserializing meshes with cloth.

• Fixed CO always automatically compiling.

• Fixed CO loading hang when a Child Object was not properly connected to a group.

• Fixed loading incorrect CO hierarchies.

• Fix Mutable compilation crash.

• Fixed crash during the generation of a Mutable Mesh from a Static Mesh.

• Fix crash when converting constants that had as a child an IM_REFERENCE.

• Made the "Material Modify" editor node ignore the non-input pins during the node compilation.

• Fixed case where an error during the COI update made it still eligible for being updated each time the ticker got ticked.

• Fixed crash when opening an empty CO.

• Fixed crash in ConvertSkeletalMeshToMutable when the SkeletalMesh is missing.

• Fixed late initialization of the NeedsCPUAccess flag for FSkinWeightVertexBuffer.

• Fixed crash when opening the Code / Graph Viewer without model.

• Fixed parameter discoverability issue when multiple UVs require layout generation.

• Fixed crash with Mesh and Image parameters being nullptr.

• Fixed reported Task times in Performance Analyzer.

• Fixed Dataless crash when streaming inline SKM LODs.

• Fixed modifiers not being applied correctly with optimization None.

• Fixed GetModelResources crash when cooking.

Deprecated:

• Deprecated ComponentIndex in favor of ComponentName in CustomizableSkeletalComponents. Moved the remaining CustomizableSkeletalComponent properties to private.

• Removed the option to generate 'Only manually created LODs' in favor of automatic LODs.

Control Rig

New:

• Control Rig Physics

  • Implements the per-body PhysicsBlendWeight.

  • Setting the StepPhysicsSolver alpha value to 0, disables simulation, switches the node to a cheap pass-through mode, and prepares the simulation to restart if alpha is subsequently set > 0.

  • Add support for acceleration vs force mode (a simple toggle) in controls.

  • Add an option to scale damping by inverse mass. This is to allow users to choose whether damping acts to simply calm down the simulation, vs behaving more like drag (air resistance)

  • Support resetting the simulation if the absolute time between updates is above a threshold.

  • Improves the way that settings for the solver and simulation space motion etc are exposed.

  • Adds "GetPhysicsBodyExists" and similar Get calls for the other types of component.

  • Add cvars for debug visualization control.

  • Control Rig Physics now supports convex shapes. Note that this is especially useful when importing from a physics asset using convex shapes.

  • Control rig physics supports continuous collision detection (CCD) as an option on the solver and individual bodies.

  • Control Rig Physics plugin is now enabled by default.

  • Control Rig Physics optimisations/speedups.

  • Improve tooltips/help.

  • Rename BonesToUse to BoneMask in relevant nodes.

  • Improve instantiation from a physics assert, to let modular rigs work better. Now physics on the whole character can be instantiated limb by limb, and the junctions will not be missing joints/controls.

  • More get/set functions exposed to the control rig graph.

• RigVM

  • Added new math node "Get Rotation from X Vector"

  • Added "Sphere Trace By Profile" and "FRigUnit_LineTraceByProfile"

  • Control Rig/RigVM: Add support for text rendering with DrawText().

  • Allow structs within RigVM to implement ImportText for cache management purposes.

  • Improve usability of the RigVM Print node - defaults to display for a single frame, and the duration is more clearly exposed.

  • Clarify RigVM help text for some trig functions.

    • Adds a maths "Wrap" function to RigVM.

  • Removed RigVM cached handles array from instances, as a memory saving optimization This also eliminates the need to patch handles for each instance initialization (it generates patched handles on the fly for each instruction).

  • RigVM now preprocess handles using offsets at CDO creation Added cvars to allo tweak / disable RigVM parallel_for on some platforms.

• Add an option to directly edit redirector nodes.

  • New option in Editor Settings → Rig VM Editor → Direct Reroute Node Editing, disabled by default.

  • When enabled, reroute nodes are dragged by default, and create connections with Ctrl-Drag.

  • When enabled, when double clicking near a line, a reroute node is created and connected to the nearby line.

• Control Rig Dynamics: This is a new experimental plugin that adds support for fast physically-based dynamics in Control Rig. This allows simple cosmetic dynamics to run significantly faster than the equivalent Control Rig Physics setup, making it better suited to gameplay scenarios.

• Rework space editing, add multi-editing support.

  • When selecting multiple controls in a viewport, spaces can now be edited for all selected controls.

  • The add spaces menu now only shows valid spaces.

  • The bake spaces dialog now shows custom spaces.

  • Adding the default parent no longer adds a duplicate parent entry, the default parent is briefly highlighted instead.

• Add an option to show only empty sockets in the schematic viewport, defaults to true.

• Add cut, copy, paste and delete commands to the graph node's right click context menu.

• Control rig physics and dynamics: Add debug UI for physics and dynamics, activated by buttons on the Control Rig editor toolbar. Also added to the Tools→Debug menu, as this can be used during PIE too.

• Make baking to control rig procedurally equivalent to the UI codepath in terms of how we deal with pre-existing control rig tracks.

• Allow physics control rig users to differentiate collision against world bodies by collision type (i.e. physics, query, probe). Also refactor ISM specific code to simplify implementation.

• Improve settings.

  • Separate menu settings between level editor and asset editor.

  • Settings for the level editor are now stored where applicable.

• Curves referenced in the graph are now highlighted in the Curve Container tab.

• In a Control Rig Graph dragging from a node and pressing F now spawns a for each node.

• Fix for CRP to correctly add world bodies that are owned by instanced static mesh components.

• Add a new option "Compile Resets Solve Mode" in the Event Queue menu, default to true.

• New hotkeys Editor Viewport:

  • Bones: Alt-B

  • Controls as Overlay: U

  • Nulls: G

  • Sockets: H

  • Axes on Selection: J

  • Graph:

  • Profiling: P

  • Next Event Queue: M

  • Prior Event Queue: Shift-M

  • Toggle Forwards and Construction: Ctrl-M

  • Rig Hierarchy:

  • New Socket: Ctrl-K

  • Module Hierarchy:

  • Show Secondary Connectors: Ctrl-Shift-1

  • Show Optional Connectors: Ctrl-Shift-2

  • Show Unresolved Connectors: Ctrl-Shift-3

  • Duplicate: Ctrl-D.

• Add an option to duplicate Modules from the Module Hierarchy context menu.

• Rig modules now can add an Array Size Rule for Connectors to express the expected number of connections.

• Searching the Module Hierarchy in Modular Rigs now also finds entries by the Control Rig Module class when said column is visible.

• Anim Outliner, Anim Details, Sequencer and Curve Editor now show Controls in the same order.

• Set Default Match is now a template node that accepts both single connectors and an array of connectors.

• The Modular Rig Hierarchy Tree View now supports recursively expanding/collapsing elements by Ctrl-clicking nodes.

• Creating a Control Rig asset in the content browser now allows picking Rig Module in addition to Control Rig and Modular Rig.

• Connectors in Modular Rigs can now also be dragged from the details panel.

• Improved columns in the Modular Rig Hierarchy.

  • Columns can now be shown or hidden when right clicking the header.

  • Added new columns Module Class and Module Tag, both hidden by default.

• Modular Rigs now show the Schematic Viewport when dragging modules.

• The Modular Rig Editor now shows the class name and a browse to asset icon along with the class path in Details.

• Mirror settings are now stored per project per user.

• The Modular Rig Hierarchy editor now stores the connector visibility filters per project per user.

• Views where Connectors could not be reordered now show a small icon to declutter the view.

• Modules in Modular Rigs now show a combo box to select Control Shapes, including Shapes from the Shape Libraries of the Module's Control Rig, Shape Libraries of the Modular Rig and Direct Mesh Control Poly Groups.

• Connectors in Rig Modules now have a description property which the Modular Rig Hierarchy displays as a tooltip.

Bug Fix:

• Control Rig Physics

  • Clamp strength so that values < 0 don't cause unwanted behaviour.

  • Fix parent-space controls not finding the parent body when instantiating from a physics asset.

  • Fix serialization of shapes (name and ContributeToMass).

  • Ensures that world objects get initialised in the collision system properly: Fixes problems with objects not colliding unless they have moved.

  • Improves/fixes some automatic collision shape generation.

  • Collision fixes for when bodies have no shapes.

• RigVM

  • Fix for inline edit conditions not getting updated when toggled.

  • Missing comma in python print for add_reroute_node_on_pin.

  • RigVMEdGraph call PostEditChange after calling modify in RemoveNode.

  • Update RigVM function reference nodes when adding or removing variable references to the contained graph.

  • Avoid RigVM crash when there is a function with a missing pin in the injection data.

  • Disabled RigVM function parameter customization on aggregate nodes.

  • Fixed RigVM NotEqual operand.

  • Fixed RigVM debug info use after delete leading to crashes.

  • Fixed RigVM equal dispatch node type check to allow comparing compatible types, like enums with uint8 encoded enums.

• UAF

  • Fix for not being able to clear uobject references on rig vm properties via the details panel.

  • Crash fix for mixed usage of 16bit and 32bit pose indices in AnimNextControlRigPoseAdapter.

    • Fix incorrect accessor ControlRigPoseAdapter::GetGlobalPose() actually returning the local pose.

• Control rig dynamics and physics: Clear arrays during initialisation. This has no effect in normal use, but when using the COntrol Rig Construction Event mode, it prevents these arrays from unbounded growth.

• Fixed for some Control Rigs not correctly centered on asset editor start.

• Move to using a struct for world object keys to avoid potential collisions within TMap when previously using hashes as keys.

• U Rig Hierarchy::CanCauseCycle no longer ignores inactive parents, no longer ignores inactive parents, which previously could cause cyclic dependencies.

• Ensure that all run once events are cleared at the end of Execute. This prevents any custom run once events from being run every frame.

• Fix a crash in ControlRigParameterTrackEditor when Controls are selected outside of the game-thread, for example during undo/redo.

• Fixed Control Rig copy hierarchy reallocate elements breaking the target elements subindex.

• Fix for an issue where get user data was failing to find uobject types in the RigVM asset registry due to incorrect formatting on the type strings.

• Control Rig crash fix for use after delete at control shape creation.

• Fix issues with rendering bones and local rotation axes in level editor and asset editor.

• Frame Selection (F) now works in the Control Rig Editor.

• Modular Rig modules can now be rearranged within their parent after undo/redo.

• Control rig assets are dirty upon re-opening.

• Fixed Control Rig AST generation, to avoid function entry variables being included in scope blocks.

• Adding the first bone to a Control Rig and undo/redo now restores the bone.

• Fixed Control Rig function parameter type selection not allowing array types.

• The Modular Rig Hierarchy now allows reordering Modules within the same parent as expected.

• Connector Rules are now respected when selecting elements in Modular Rig Details.

• Fix an issue in the Modular Rig Editor where the reorder handle for Array Connectors was not visible.

• Fix various issues in Module Hierarchy's functionality.

  • Mirror modules now mirrors children and retains the mirrored sub-hierarchy.

  • Fix details are not refreshed when a connection array is cleared in the module hierarchy.

  • Fix clearing connector arrays with related button did not clear the array.

  • Fix the details view did not update when the connector array was cleared.

  • Fix the last connector in a connector array could not be removed.

• Fix for the GetChainLength function to return the total chain length instead of the average.

• Control Rig Modules Connector Details no longer show the connectors as array when the Is Array property is set to false.

• The Rig Hierarchy and the Module Hierarchy now keep their selection and expansion after compiling.

• Fix issues where the Module Hierarchy did not always allow scrolling. Issues where Connectors are displayed in the Module Hierarchy remain in certain cases.

• Fixed debug draw smearing on Control Rig.

• Fix an issue where Control Shapes remained partially selected in Modular Rigs when a Rig Module was compiled.

• Fix Control Rig import from text heap use after free, due to the relocation of the element transforms after adding a new element.

• Fixed Modular Rigs overrides causing an infinite recursion in the tagged property serialization.

• Fixed a Control Rig crash adding a graph after renaming another newly added graph.

Deprecated:

• Deprecate FRigControlElement::Settings direct Blueprint access -- adds deprecated UPROPERTY so existing BP graphs still work with warnings, and adds GetControlSettings(Key) BlueprintCallable as the migration target.

• Cleaned deprecated methods from UAF (up to 5.6).

• Cleaned deprecated methods from RigVM (up to 5.6).

• Cleaned deprecated methods from Motion Warping (up to 5.6).

Deformer Graph

Bug Fix:

• Deformer Graph

  • Fixed crash when using secondary skeletal mesh component binding in a deformer graph.

  • Fixed various crashes and assertions in Deformer Graph when it is used in a Control Rig while Asset Save is ongoing.

• Fix issue where deformer settings were lost during bp component reinstancing process.

Gameplay

New:

• Pose Search

  • PoseSearchDatabase editor multi selection improvements.

  • Pose Search databases created for Chooser Columns now default to BruteForce, since KD Tree usually fails with external filtering.

  • PoseSearchColumn support for unique PoseSearchDatabase per row.

  • PoseSearchColumn (motion matching integration with choosers) bug fixes.

  • PoseSearch plugin motion matching drawing bug fixes.

  • Added a project setting (Project Settings → Pose Search → MaxDatabaseEditorPreviewActors, default 50) that caps the number of actors spawned in PoseSearchDatabase editor.

  • U Pose Search Interaction Asset::CalculateWarpTransforms improvements.

  • Added Experimental BlueprintCallable UPoseSearchInteractionLibrary::MotionMatchMulti, new API to perform multi character motion matching searches without any frame delay.

  • New PoseSearch plugin Blueprint callable OverridePoseHistoryFromOwningMesh function to override the pose history pose with the mesh pose to enable, for example, motion matching physics poses.

  • Added UAnimNotifyState_PoseSearchSamplingRange notify state, used to to include animation segments into PoseSearchDatabases.

  • Strip out disabled PoseSearchDatabase animations during cook.

  • Fix montage trajectories not working when operating on pawns not characters.

    • Make montage prediction CVar `a.PoseSearchTrajectory.UseWarpedMontage` affect Mover / when using predictor as well.

  • Add support for experimental posesearch generation of warped montage trajectories.

    • Remove all direct actor transform references from root motion modifiers.

    • Add 'UMotionWarpingTrajectoryAdapter' which may optionally exist on a 'UMotionWarpingComponent' to predict trajectory.

    • Add `FRootMotionModifierSwapState` to store warping state pre-prediction and restore state post prediction.

    • Add "Prediction Mode" to 'UMotionWarpingComponent' where it uses the swap state / new adapter to predict warped trajectories.

    • Add Experimental `UPoseSearchTrajectoryLibrary::PoseSearchGenerateWarpedTransformTrajectory` to generate warped trajectories.

    • Add `GVarPoseSearchTrajectoryUseWarpedMontage` to enable warped montage trajectories by default.

  • Improved UPoseSearchInteractionAsset warping calculations.

  • Removed some UE 5.6 deprecations from PoseSearch plugin.

  • Optimized PoseSearchDatabase DDC key generation by removing template objects.

  • Renamed few motion matching stats from the PoseSearch stat group (Search Brute Force, Search PCA/KNN, Search VPTree, Search Event into PoseSearch Brute Force, PoseSearch PCA/KNN, PoseSearch VPTree, PoseSearch Event).

• Account for mesh scale when calculating Motion Warping warp points. Enable with a.MotionWarping.UseMeshScale.

• Exposed UMotionWarpingComponent::FindWarpTarget as BlueprintCallable.

• Add handling for angular velocity to trajectory history tracking so that spinning platforms are handled properly.

• Add Anim Node Functions to support applying a delta to the offset root bone's internal simulated transform.

• Added UCurveFromSyncMarkersModifier to generate a curve from synch markers.

• Added Blueprint-exposed ResetSync function to reset sync group information on Anim Graph.

• Removed experimental MotionMatchingInteraction node.

• Add a OnInputDeviceHardwareInfoAvailable delegate to the input device mapper, which allows for code to bind to connection events and be guaranteed to run before other systems like Common Input/User code. This makes it possible for the UInputDeviceSubsystem to query the FInputDeviceScope, and make the necessary associations of the known hardware device Id to the new FInputDeviceId.

• Sync group support for follower blendstacks.

• Optimized motion matching interactions performance with a custom hash grid.

• Defaulted motion matching trajectory generation in mesh space rather than using the Character.View.Rotation.Yaw when the character is set to orienting the rotation to movement.

• Added URootMotionModifier_Blueprintable, new MotionWarping URootMotionModifier blue print overridable.

• Motion matching interaction performance improvements.

Bug Fix:

• Pose Search

  • PoseSearchDatabase fix for not being able to copy paste in an empty database.

  • PoseSearchDatabase DDC key generation fix, to support objects with duplicated down dependencies.

  • Fixed a bug where for inconsistent past velocities in motion matching due to history points being offset by delta time, causing noise in past velocity when delta time is not constant.

  • Fixed PoseSearchDatabase editor preview of static mesh attachments.

  • Fixed PoseSearchSchema velocity channel debug visualization.

  • Fix for PoseSearchDatabase indexing looping animation assets.

  • Fixed crash in FAsyncPoseSearchDatabasesManagement::RequestAsyncBuildIndex when database dependent animation assets failed to compress.

  • Fix for missing PoseSearchDatabase indexing on reverting and reloading dependent assets.

  • Fix for UPoseSearchFeatureChannel::CanBeNormalizedWith.

  • Fix for missing FMemMark(s) in FPoseSearchColumn::Filter and FPoseSearchColumn::SetOutputs.

  • Fix for PoseSearchDatabase DDC key determinism when supporting Choosers PoseSearchColumns.

  • Making sure there're no flying animation tasks when on game thread by calling GetProxyOnAnyThread, so it's safe to access animinstance variables in UPoseSearchLibrary::MotionMatch.

  • Fix for UPoseSearchLibrary::MotionMatch crashing when reusing an invalid continuing pose from a previously evaluated schema.

• Motion Warping

  • Add an "AdditionalRotationOffset" in the root motion modifier that allows rotational offset to be specified per animation. This avoids conflicting rotations when warp points are used by multiple different actions. Note that any setup using a rotational offset with facing mode will need to be manually adjusted (this was introduced in 5.7).

  • Deprecated EMotionWarpRotationType::OppositeFacing and EMotionWarpRotationType::OppositeDefault since they can be achieved with an additional rotational offset of 180 degrees (existing data will be automatically converted).

  • Stop using the warp point's rotation offset when in facing mode.

• Fix for crash while changing levels because of invalid FRewindDebuggerTrajectory::WorldToVisualize.

• Fix to allow the DisplayWorldId to be set while analyzing local sessions. Without this, the debugged mesh is lost after the PIE session ends.

• Fix montages do not mark blending out sources as inactive.

• Fix for previewing game generated pose search debugger data with the editor.

• Fix for SearchThrottleTime not working properly in FAnimNode_MotionMatching::UpdateAssetPlayer and FMotionMatchingTrait::PreUpdate.

• Fix for crash in USkeletalMeshComponent::ForEachBodyBelow when instantiated Bodies do not match the SkeletalBodySetups in the Reference Skeleton Mesh.

• Fix for FAssetIndexer::Process crashing on schemas with roles improperly setup.

• Fix issue where GetPoseIndex could return an invalid pose index when there are multiple sampling ranges on the same animation asset.

Deprecated:

• Removed 5.6-deprecated PoseSearch methods.

• Deprecated: UPoseSearchFeatureChannel_Curve::BP_GetCurveValue, UPoseSearchFeatureChannel_Heading::BP_GetWorldRotation, UPoseSearchFeatureChannel_Velocity::BP_GetWorldVelocity, UPoseSearchFeatureChannel_Position::BP_GetWorldPosition, in favor of UPoseSearchFeatureChannel_Curve::BP_GetCurveValueFromContext, UPoseSearchFeatureChannel_Heading::BP_GetWorldRotationFromContext, UPoseSearchFeatureChannel_Velocity::BP_GetWorldVelocityFromContext, UPoseSearchFeatureChannel_Position::BP_GetWorldPositionFromContext, taking the more versatile FChooserEvaluationContext as input.

IK and Retargeting

New:

• IK Retargeter

  • Override Set editor: Add Child, Search Bar, Keyboard Shortcuts, Duplicate, Reordering

    • Added DuplicateRetargetOverrideSet() to the controller API (Blueprint/Python callable). Creates a new override set with a unique name, copying all property overrides, parent assignment, and active-by-default state from the source set.

    • Added "Duplicate" entry to the Override Set tree view context menu between Rename and Unparent.

    • Add Child: Context menu action to create a new override set parented under the selected set.

    • Search Bar: Enabled the built-in details panel search bar for the Override Set editor.

    • Reordering: Added ability to reorder override sets in override set tree.

    • Keyboard Shortcuts: Delete/Backspace deletes selected override set, F2 renames it.

    • Override Set Reordering: Fixed drag-drop to distinguish between reordering (AboveItem/BelowItem) and parenting (OntoItem). Added DisplayOrder field for persistent sort order. Reordering makes the dragged set a sibling of the target at the correct position.

  • Expose bRetainAdditiveFlags to RunBatchRetarget Blueprint/Python API.

    • Added bRetainAdditiveFlags to FIKRetargetBatchOperationInputs so that Blueprint and Python scripts can control whether additive animation attributes are preserved during batch retarget.

• Updated all 17 biped templates to split the existing LeftLeg/RightLeg chains: LeftLeg/RightLeg chains now end at the ankle/foot bone (previously ended at ball/toe) New LeftFoot/RightFoot chains cover the ball/toe bone.

  • IK goals remain on the leg chains, now created at the ankle/foot bone.

  • Updated FBIK auto-setup defaults:

    • SubIterations: 0 → 10

    • Goal ChainDepth: 0 → 2

  • Updated Biped Templates,

  • Added new Templates for Blender Rigify and Meshcapade.

• Add override set dropdown to Batch Retarget window When using a manually supplied IK Retargeter in the Batch/Auto Retarget window, there was no way to select override sets.

  • Added a dropdown (FName with GetOptions) that lists available override sets from the assigned retargeter asset. Selected override set is applied to both the live preview viewport and animation export. Dropdown is disabled when using auto-generated retargeter.

• RigMapper Definition editor graph improvement: Made importing inputs/outputs from Control Rig optional through a check box in import dialogue in order to reduce clatter.

• Improved RigMapper Definition editor graph Comment nodes to fully enclose selected nodes and to trigger on "C" key command.

• Improved validation messages and notifications for RigMapper Definition editor graph. Notifications are now displayed in the graph header. Before they could be seen only in log.

• Added Math Operations feature to RigMapper Definition with a corresponding node in RigMapper Definition editor graph. This op includes all unary, binary and N-array standard mathematical operations selected through the drop down box.

• Improved zooming in/focusing a node and all connected nodes by lowering opacity to non selected nodes and zooming in/out to capture selected ones.

• Implemented Comment node feature for RigMapper Definition graph.

• RigMapper refactoring to include numerous quality of life changes:

  • Improved Undo/Redo system.

  • Persistent node positions between sessions (Graph is no longer recreated every time it is opened).

• Added feature which imports Input curves from Skeletal Mesh.

  • Fixed a problem with RigMapper Definition cache not being cleared when modified.

• Updated IKRetargeter Curve OP stack:

  • RigMapper Op is now a sub-operation of CurveRemap Op.

  • RigMapper divided into RetargetRigMapperUserDataOp which uses RigMapper Definition embedded in target mesh UserData, and RetargetRigMapperOp which contains single RigMapper Definition data asset.

  • Added possibility to select multiple RigMapper Ops in a single substack.

• Implemented RigMapper Definition Graph pin interactions:

  • Added support for breaking links from a node.

  • Added support for moving links from one node to another.

  • Implemented support for adding new connections by dragging and dropping to a different node.

• IK Rig: Allow enabling/disabling anim graph node w/ cvar a.animnode.IKRig.Enable.

• Quality of Life improvements:

  • Allowed adding more pins to nodes and automatically generating connections to other nodes.

  • Fixed a bug with importing a Definition from JSON file.

  • Added constraints when removing pins so the minimal required number of pins are preserved depending on the feature.

  • Improved memory management and performance.

• Reimplemented RigMapper Definition Graph to be interactive:

  • Nodes can be moved around, although position will not pre preserved on reopening.

  • Nodes can be created from a connection or standalone though a context menu.

  • Nodes can be updated through details panel on the right side.

  • Added a Context menu on right click on node or graph.

  • Nodes can be relinked and links can be removed.

Bug Fix:

• Fixed and improved RigMapper Linked Definition validation to include NullOutputs which are subsequently used as inputs.

• Relaxed validation of hanging inputs and outputs for RigMapper Linked and Baked Definitions to allow pass-through with a warning.

• RigMapper definitions tongue fix on RM_CDH_FNM, RM_MHH_CDH and related Linked Definitions and Baked definitions.

• Updated RM_CDH_FNM rig definition to address an issue with inverted corner sharpen and upper eyelid controls.

ML Deformer

Deprecated:

• Cleaned deprecated methods from MLDeformer (up to 5.6).

Physics Control

New:

• Physics Control Component

  • Add BP support for specifying collision ignore/include pairs - Enable/DisableCollisionBetweenBodies.

  • Enable/disable angular drives applies to slerp as well as twist/swing.

  • Make sure that limb-generated controls get automatically added to a set with the limb name.

  • Fixes for Physics Control Component names, so they're never called "". Note that this will change the names of some controls/modifiers, and if those are being referenced explicitly (by name) the assets will need to be patched up.

    • Functions added to log controls/modifiers.

    • Adds checks that controls/modifiers/sets that are passed in are valid (and optionally warns if not).

• Drives now have a Join Limit Violation Response. The available options are: Clamp the skeletal animation drive targets to joint limits, or Widen limits to accommodate the target. In addition to either respecting the joint's limit or the animation, this prevents spurious forces and torques present when drive and limits are fighting (response 'None' option).

• PhysicsControl plugin is now marked as ready for production use.

• Support for applying forces in the control rig physics and RigidBodyWithControl animation graph nodes.

Bug Fix:

• Physics Control Component: Addresses various problems with tick ordering/dependencies so that 1. it waits until the input pose is ready and 2. it ensures the tick is not pushed into PostPhysics by (for example) CharacterMovementComponent when on dynamic floors.

• Guard against the RequiredBones container in RBAN and RBWC InitializeBoneReferences having an empty reference pose (to prevent a crash).

• Fix for bad memory access when world collisions are enabled in RigidBodyWithControl or RBAN.

• Prevent PhysicalAnimationComponent crash if physics blending is enabled mid-tick.

Runtime

New:

• Anim Montage

  • Fixed montage forced position handling during advance if forced position gets updated multiple times without advancing the montage in-between e.g. on sequencer loops or with URO enabled Guarded by CVarUseForcedSequencerMontageLoopBehavior(a.Montage.UseForcedSequencerMontageLoopBehavior). Turned off by default.

  • Added additional safety checks in FAnimMontageInstance::Terminate().

  • Added guarding against negative blend times on montages.

  • Added CVar a.Montage.UseForcedFromPositionAsSubStepOrigin - if ForcedNextFromPosition is set, use it as the sub-stepping origin in FAnimMontageInstance::Advance instead of the previous internal position. Enabled by default.

• UAF

  • Add OffsetRootBone anim node.

  • Add variable container name to variable trace.

  • Translational retargeting trait.

  • Added the option to display trajectory velocity in debug log.

  • Added new OverrideRootMotionTrait.

  • Add InputValue anim node/op.

  • Add FPoseValueBundle as a typed pose overlay for FValueBundle.

  • Implicit cross-skeleton remapping at graph input boundary. Remaps poses automatically when a foreign skeleton enters a graph via PushPose so node authors never deal with cross-skeleton concerns.

  • Add the ability in UAF to specify the end tick group for events.

• RigVM

  • Add package path to some rigvm compile error reports.

  • Add CharacterMovementComponent to allowed class types in RigVM.

• Add CVar to suppress duplicate anim node slot names warning.

• Add CVar that allows for using MovieScene GUID rather than channel hashing for partial-UAnimSequencerDataModel hash (significant speed-up, downside is MovieScene GUID invalidation is non-deterministic).

• Added additional pose validity checks when getting the target transform of a bone socket references.

• Added additional pose validity checks to ConvertWidgetLocation in FAnimNodeEditMode.

• Reimplementation of "Speed up UAnimSequence::CreateDerivedDataKeyHash" - drastically decreases time spend on Animation Sequence its DDC key generation.

• Added ObjectsSelected delegate interface function to IAnimationEditor.

• Added virtual keyword to FAnimInstanceProxy::UpdateCurvesPostEvaluation.

• Allow Custom Widgets for AnimNotifies.

  • Rename

    • INodeObjectInterface → INotifyNodeObjectInterface.

    • ETimingElementType → ENotifyTimingElementType.

• Allow Custom Widgets for AnimNotifies.

  • Rename

    • INodeObjectInterface → INotifyNodeObjectInterface.

    • ETimingElementType → ENotifyTimingElementType.

• Expose certain solver collision settings to RBAN and RBWC nodes to allow for improved environmental collisions. This gives parity with functionality in control rig physics. Also added a new category for the details panels to clean up the UI.

• Expose Set/Get Accumulated Time in BlendSpacePlayerLibrary.

• Added experimental Animation Layering plugin containing:

  • Copy Bone Motion Anim Node.

  • Copy Bone Advanced Anim Node.

  • Bone Mask Anim Node.

• Added Scoped Crash Data For Animations (Make animation crashes easy to debug).

• Notify States: Added the option to not merge the lifetime of notify states on concurrent plays of the same animation asset.

• Allow for notify event dispatch to be disabled on a per-mesh component basis. This doesn't prevent the notifies from being sampled but the associated events will not be dispatched at the end of animation update when the flag is set.

• Allow priority to be set on transitions to conduits so it's possible to deprioritize them vs transitions to other states.

• Marked GetCurveValueWithDefault() in AnimInstance as const.

• Fixed description of BoneIsChildOf.

• Enable animation frame stripping cvar support in editor Useful for debugging purposes.

• Exposed AnimMontages track properties to BluePrint.

• Offset Root Bone: Added support for teleporting.

• Pose History: Added Blueprint library functions to get bone data from pose history.

• Force property access pre-event graph update callsite to be invoked prior to InitializeRootNode being called. This prevents property access errors coming from anim nodes that call GetEvaluateGraphExposedInputs from Initialize_AnyThread.

• Added standard blend for Anim Graph mirroring node.

• Add user-exposed NotifyInstanceID to FAnimNotifyEventReference. This can be used in user events to tell notify instances apart.

• Added populating the error log with names of missing skeleton bones, when a mesh has bones that do not exist in the skeleton yet.

• Removed no longer used additive total bone weight array from the BlendProfileScratchData and SlotEvaluatePoseWithBlendProfiles.

• Add 'Ignore Pose Asset Source Animation Curves' property to the pose blend node.

• Marked UAnimInstance::GetCurrentStateName as const and added const correctness in function body.

• Add filter for non-additive animations in the animation editor asset browser.

• Removed deprecated functions in USkeleton (GetSkeletonRemapping, GetAssetRegistryTags, CollectAnimationNotifies, GetRawAnimationTrackIndex).

Bug Fix:

• UAF

  • Fixed uninitialized variable ContentOnly in SRigVMFunctionPicker causing state tree function binding regression.

  • Fix: ExecuteBindings_GT not gated by external prereqs added via module dependency traits.

  • Fix for multiple copies of variable instances showing up in rewind debugger for graphs.

  • Fixed check failure on shutdown.

  • Fix for GetHostTransform not reporting the correct value until the actor has moved after spawn.

• Add handling for rare cases where anim sequence memory mapping fails.

• Ensure linked anim instances created by a post-process anim instance are not reset prematurely.

• Fix ABP linked layers crash due to stale node references during cross-asset compilation.

• Fix early check for derived anim Blueprints causing crashes when parent class skeletons were deleted Add update path for derived anim Blueprints when parent skeletons mismatch or are deleted.

• Ensure anim instance functions wait for async animation updates to terminate when called from the game thread.

• Improved Animation Notify track behavior when displayed and used at non-standard DPI level.

• Fix for inaccurate root motion playback on first loop in persona editor.

• Animation Modifiers: Fix for revert and removal when bReapplyPostOwnerChange=true.

• Fixed ensure when opening Animation Sequence containing (additive) transform curve(s).

• Addressed non-deterministic cooking behavior caused by Animation Graph Slot nodes.

• Fix for Constraint AnimNode when initial weight is zero but in the future will be non-zero.

• Fix for crash in Constraint AnimNode when changing setup while running.

• Anim Montage: Fixed prematurely calling of AnimNotifyStates end events when the montage advance is driven by forced positions and their delta is zero (e.g. from a frame-locked Sequencer with unstable frame times).

• Fix missing compatible skeleton conversion when retrieving attributes.

• Get the correct compact pose bone index rather than mesh bone index.

• Fix up missing calls to initialize FK control rig hierarchy when running in lazy init mode.

• Avoid crashing when blend space sample uses a null animation sequence.

• Always preload animation sequence dependencies as MT async loading requires manual handling.

• Fixed crash when updating blend samples in a Blendspace while PIE is running in a separate window.

• Fixed crashes caused by NaN bone transforms coming from AnimNode_StrideWarping.

• Fix for potential NaN bone transforms generated inside AnimNode_FootPlacement if root is rotated exactly 90 degrees from expected approach direction.

• Set anim group follower LeaderScore to always be less than any possible leader, to avoid selecting any follower as leader if there's any leader in the FAnimGroupInstance.

• Fixed ensure in UAnimInstance::TriggerQueuedMontageEvents.

• Skeletal mesh component now refreshes the skeletal mesh asset at PostEditImport, so the skeletal mesh is not lost after a duplicate.

• Fixed crash in DebugDrawSkeleton when using 'show bones' command.

• Validated that users are not trying to apply an anim BP preview overlay to self.

• Move leader component test earlier in CopyPoseFromMesh to make sure our bone map is updated correctly.

• Make SharedContext a unique ptr to force destruction when released in FAnimNode_SaveCachedPose::PostGraphUpdate.

• Fixed issue where Additive and Blend components within an Animation Sharing setup were not locked to LOD0, causing artifacts on non-LOD-compatible target components.

• Fix potential thread-unsafe access to skeleton remapping data. In that case of FReferenceSkeleton, limit when the remapping data is refreshed to only when it's a skeleton and not a mesh that is having it's ref skeleton rebuilt.

• Fixed CopyBonesModifier for bones without pre-existing curves.

• Fix issue with blended curve container not correctly tracking when it is sorted.

• Fix to allow notifies that are sampled via AnimSingleNodeInstance to store the current playback time. This means that UAnimNotifyLibrary functions that rely on the current time can be used on these notifies.

• Enable FBoneSocket Target Pickers in Contexts Outside Anim Montages.

• Prevented crash loading into CitySample using -dpcvars=Editor.ObjectReverseLookupMode=2.

Deprecated:

• Cleaned deprecated methods from animation runtime (up to 5.6).

• Removed non-reflected UE_DEPRECATED items (5.0-5.6) spanning Engine/Source/Runtime/Engine/{Classes, Public}/Animation, Engine/Source/Runtime/AnimGraphRuntime (+ MovieSceneTracks anim nodes), and Engine/Source/Editor/AnimGraph compiler interfaces.

• Cleaned deprecated methods from LiveLink (up to 5.6).

• UAF: Fixed incorrect deprecation logic in AnimNextComponent when loading Blueprints with data inheritance on deprecated variables.

• Deprecated CachedSoftObjectPtr in USkeleton.

Sequencer

New:

• Sequencer

  • Delete Mark is now Delete Selected Marks which allows the selected marks to be deleted at once.

  • Add Mark is now Add Mark at Playhead which adds a mark at the current playhead as opposed to where the mouse was pressed.

  • Playing a sequence in the editor now honors the time bounds (selection range when set, otherwise playback range), matching rewind and key-jump behavior.

  • Playhead scrubbing can now be limited to the selection range, in addition to None and Playback Range.

  • Bake Transform is now available from the object binding right-click menu.

  • Added missing Convert to Spawnable command binding, and route Level Sequence conversions through Convert To Custom Binding so custom-binding spawnables work.

  • Bake Transform now disables the original track instead of toggling each section, matching the Bake to Control Rig behavior.

  • Add support for Material Slots Overlay Material switching and parameter animation. .

  • Assigning a spawnable to an object property now creates an Actor Reference Track automatically, so the reference doesn't go stale when the spawnable's path changes.

  • Component Attachment tracks now respect hierarchical bias, so a higher‑priority attachment section correctly overrides a lower‑priority one when they overlap.

  • The Actor Reference track now supports Completion Mode, so disabling or muting them properly restores the prior reference.

  • Jump to Next/Previous Key now respects looping. When looping is off, it no longer wraps past the first/last key.

  • Add Selection from Content Browser is now a bindable command, so you can assign it a keyboard shortcut in editor preferences.

  • The Actor Reference track (used for properties like the Cine Camera's Look At Target) has been upgraded to Sequencer's ECS evaluation system, aligning its performance and ordering with other tracks.

  • Lighting channels on primitive components are now animatable.

  • Dragging a marked frame now translates selected keys and sections along with it.

  • Pausing the game now pauses the Sequencer clock as well (opt out via Sequencer.AllowPausedClock 0).

  • The back/forward mouse buttons now navigate forwards/backwards through sequences, matching the Blueprint editor's tab navigation.

  • Snap to Markers while scrubbing now snap to the playback start/end and selection start/end frames.

  • Markers are now also selected with Select All in Selection Range, Select Forwards, and Select Backwards. Added a new option to Select Markers in Selection Range.

  • The Add Track button for Subsequences now allows creation of custom Level Sequence subclasses.

  • Remove DisplayName="Anim Sequence" for MovieSceneSkeletalAnimationSection because it conflicts with Anim Sequence assets.

  • Add a way for stitch track to work with Animation Blueprints. This is a bit of a workaround for the issue of pose history not being able to be both read from and written to easily via an attribute, which is necessary for the stitch track. Now, the user can add an 'OverridePoseHistoryName' which, in animation Blueprint mode, will look for a pose history node tagged with that name and pull the pose history from it for use in the stitch track. This allows the pose history node to be _after_ the sequencer target node, which is necessary for blending out to work correctly. In addition, we set up an example properly in the AnimSandbox to show this working.

  • Deselect marked frames when keys and sections are also deselected. Disallow marked frame movement when they are locked.

  • Limit Viewport Selection is now in the viewport menu whenever a sequence is active (was Animation-Mode-only); UMG and Actor Sequence get the button in their own toolbar.

• Anim In Engine: Control Rig use ECS evaluation by default Users can fall back to legacy evaluation with: ControlRig.UseLegacySequencerTemplate true.

• Add SequencerTools toolset for AI-driven sequence creation and editing.

• Added call to Global Dependency Graph update cache in OnAllModuleLoadingPhasesComplete to prevent the graph's cache to update when the first sequence is played. In the event that a plugin/module that mutates this graph loads after OnAllModuleLoadingPhasesComplete, the cache will be invalidated and will be updated when the first sequence is played.

• Sequence Validator: Fixed Whole Section Ranges rule reporting incorrect results.

Bug Fix:

• Sequencer

  • Visibility Track keys are now correctly set with their current values. Visibility is inverted from their Hidden property and the setting of the key was not correctly inverted.

  • Fix FVector2f/3f/4f tracks dropping keys silently UnpackChannelsFromOperational(const FFloatIntermediateVectorand) was writing FMovieSceneDoubleChannel entries, but UMovieSceneFloatVectorSection stores FMovieSceneFloatChannel curves. When keying, the channel proxy lookup returned nullptr and the key was silently dropped.

  • Cooking a project that uses Time Warp tracks inside child Level Sequences no longer fails with an "illegal reference to private object" error.

  • The camera cut tracks which have preroll now take into account the instance transform data of a level sequence which is passed to the streaming manager.

  • Update the possessed object class when matching possessable GUIDs (including ones that bind to spawnables), so bindings no longer hold a stale class.

  • Conditional sections inside a subsequence now evaluate correctly when a parent sequence is conditionally disabled.

  • Sequences with camera rig rails are no longer incorrectly marked dirty on save. Spline components in these camera rig rails are just visualization components, and those don't need to be regenerated or have their physics state be recreated on save.

  • Fixed a RepLayout mismatch from an editor-only field in MovieSceneSequencePlaybackSettings.

  • The entity system threading model is now refreshed at each call site after ScheduleTasks, instead of inside ExecutePhase where it was computed too early.

  • Fix race condition in TEntityTaskComponents::Schedule_PerAllocation Schedule_PerAllocation on TEntityTaskComponents (the unfiltered path) was setting bSerialTasks = false, making it behave identically to Fork_PerAllocation and allowing multiple allocations to run in parallel on different threads. This violated the Schedule_ contract that guarantees serial execution of ForEachAllocation calls. The filtered variant (TFilteredEntityTask::Schedule_PerAllocation) and both Schedule_PerEntity overloads correctly set bSerialTasks = true.

  • Film overlay options menu commands no longer stop working because they were bound to a transient widget that could be destroyed when the toolbar refreshed.

  • Dragging the selection range end with the time slider now sets it as exclusive, matching the playback range behavior.

  • Fixed the inverse sequence transform calculation, correcting subsequence time mapping.

  • Setting the selection range start/end now respects the snap interval.

  • Hide Selected / Isolate Selected with no tracks selected no longer hides or isolates every track.

  • When importing an fbx, tangents are now negated when Force Front X-Axis is enabled, keeping curve shapes consistent under the flipped axis.

  • Spawn template creation now guards against a stale object of a different class occupying the same name under the same outer.

  • Material Parameter Collection tracks no longer lose their derived display name on PostLoad when the stored name was already empty.

  • Renaming a subsequence while viewing through it no longer crashes.

  • Fix bug in ECS Control Rig that left the anim instance in an incorrect state after baking an anim to control rig requiring clicking on the control rig track to get it to work correctly. This was caused by the skel anim system restore state triggering an anim instance reset after the control rig had set the new anim instance. .

  • Remove redundant RelevantComponent from UMovieSceneSkeletalAnimationSystem RelevantComponent was set to SkeletalAnimation in the constructor, which caused IsRelevant() to short-circuit to true whenever any entity had a SkeletalAnimation component, bypassing IsRelevantImpl. This meant the system would get linked even when all skeletal animation entities had the AnimMixerPoseProducer tag, which IsRelevantImpl correctly filters out. .

  • Generating a track/section/key from the keyframe button in the details panel now correctly resolves nested array properties (ie. MyArray[0].bVisible).

  • Bake Transform now gathers key times from all sections of a transform track, not just the first.

  • The Perlin noise menu now uses the display text instead of the raw channel name.

  • OnQueueSubtitles / OnAudioFinished / OnAudioPlaybackPercent delegates are re-bound (or cleared if unbound) when an AudioComponent is recycled across plays.

  • Clicking on the Render Movie button will now respect the Movie Render Queue job type (i.e. Movie Graph).

  • The object binding menu now only traverses bound objects, so spawnable template components aren't accidentally bound to new bindings.

  • Pinning a track no longer swaps the main track area's view model with the pinned area's, keeping the two views properly separated.

  • Removed ALevelSequenceActor dependency from FLevelSequencePlaybackContext.

  • Fixed a bug where conditions were not actually checked in subsequences.

  • Compiling a Blueprint while a sequence is open no longer triggers a pre‑animated state restore that could race with async loading.

  • Defer outliner reparenting that previously happened mid-iteration, fixing potential instability.

  • Toggling Net Addressable Name on a spawnable now sticks. It's no longer reset every time the object template saves.

  • Property bindings that resolve to a non‑existent array element are now flagged as invalid, instead of silently failing or evaluating against stale data.

  • Camera Cut tracks set to "Keep State" now restore to the correct view target on repeat playback, and Keep State sections following Restore State sections keep animating their properties instead of snapping back when the prior section ends.

  • Tracks that rely on cleanup callbacks (like Control Bus modulation on audio tracks) now release their resources correctly when you close Sequencer after a Play-In-Editor session.

  • Editing a property on a character's mesh component in Sequencer no longer snaps its animation pose back to the reference pose. The pose now updates correctly whether you select the actor or the mesh first.

  • Skeletal mesh animation pose no longer resets when you edit a property on a component (subobject) of the actor.

  • Fixed not being able to set just the X, Y, or Z channels of a transform for a skeletal mesh.

  • Camera Cut and Cinematic Shot thumbnails only update during PIE when the PIE world is the one bound to Sequencer, so MRG/MRQ runs don't spuriously refresh them.

  • Fix issue with baking code (and other code) that uses FindSpawnableObjectTemplate in the case that the guid passed in is a possessable that is possessing a spawnable in another sequence. We now check for that.

  • Fix crash when closing Sequencer during deferred modification flush We do this by suppressing the deferred modification flush events during the destructor.

  • Fix crash when compiling sequences with null tracks Runs 'RemoveNullTracks) before calling CompileTrack() to prevent crashes when a sequence contains null track references. We need to track down what is causing tracks to be null, but this should fix the crash as it currently exists.

  • Fix Control Rig ECS crash that happens with dynamic rigs that change the control rig channels mid evaluation. To fix this we hold a hash of the channel list in the control rig component data and if it changes we re-copy the channel pointers into the ecs component or unlink if channels no longer exist. .

  • Sections with no channels are again considered keyable (regression fix for keyable detection).

  • Fix crash when keying non-object properties in ObjectPropertyTrackEditor Adds a check to make sure the property is actually an FObjectPropertyBase before calling GetPropertyValue(). This prevents a crash when a non-object property is incorrectly routed to this track editor, as the type size assertion in GetPropertyValue would fail. fix animation/sequencer.

  • Delete Channel no longer fails to delete when only the first name in the path matches. It now matches the last name in the path which is the actual channel name.

  • Splitting or trimming a section now places boundary keys with the correct values and preserves each key's original interpolation type, so a linear curve stays linear instead of being forced into a cubic S‑curve.

  • Fixed crash when a level sequence has a null track.

  • Fixed a crash that could occur when evaluating sequences with transform origins gathered from multiple subscenes in parallel.

  • A Template Sequence section's Hierarchical Bias now initializes before config can overwrite it, so per-section overrides stick instead of inheriting the config default.

  • The viewport no longer jitters when the aspect ratio is animated.

  • Sequence players set to loop now remember their loop count after playback ends. Restarting a looping sequence plays as a loop instead of playing once and stopping.

  • Camera Cuts and other pinned tracks no longer disappear from the timeline when dragged into a folder. Sequencer now blocks drops into folders with a mismatched pinned state and shows no drop preview.

  • The time-display UI now refreshes after subsequence nested transforms update, so local time reflects the current context instead of the previous one.

  • Editing the Level Sequence Actor's Transform Origin now marks the sequence dirty so the editor re-evaluates it.

  • Whether using anim Blueprints or custom mode, the previous anim instance gets force re-initialized after sequence is over, potentially resetting data stored in the AnimInstance unnecessarily. Previously this would only occur if the skeleton changed, but we attempted to address an issue where if Custom Mode was used, the previous anim instance was getting uninitialized anyway, and would now be stuck in an uninitialized case. That fix was a bit overzealous however, as this forced re-initialization was even occurring for cases where animation Blueprints were used and we weren't switching anim mode or anim instances. This change only re-initializes if Sequencer changed (and is now restoring) the anim instance.

  • Fragment type strings for the Universal Object Locator are now encoded/decoded so characters that are illegal in object names survive serialization.

  • The audio track no longer crashes when its played from an Actor Sequence.

  • Dragging the time range slider now properly accounts for display scaling on the desktop.

  • Resolving setter functions for bool properties now strips off the leading 'b' (eg. SetVisible matches the bVisible property).

  • Sequencer no longer expands procedural channels (like Perlin noise) to the keying time when adding keys to neighboring channels. Noise tracks keep their original length.

  • Audio in Sequencer no longer restarts incorrectly when the playhead jumps, and audio that was paused or stopped stays paused instead of being restarted by a forced time‑sync.

  • Control Rig: Fix Sequencer space channel evaluation in ECS path , [at]benoit.gadreau.

  • Fixed crash on EndPlay when using a Sequencer that contains a Spawnable ChaosCacheManager.

  • Sequencer Media track: Drag/drop of media onto a track no longer crashes.

  • Sequencer ECS Control Rig: Fix issue where additive section weights were getting double-applied. The code didn't quite match the old eval template- we need to only apply weight to absolute sections since it already is getting applied to additive sections via the parameters themselves getting weight applied.

  • Sequencer Scripting: Add Key In Channel now honors the Sub Frame argument when Time Unit is Display Rate.

  • Sequencer Control Rig: Fix issue where if multiple parameters with different types have the same name it can prevent the right parameter from being keyed. [at]ue-sequencer

• Re-added logic to handle Pasted Actors when pasting bindings.

• Fix to ensure that control rig shape actor is parented to the root component of the actor it is driving. This prevents circular dependencies for actors that don't have the root component as the default attachment component when a control rig is then attached to them.

• Movie Scene: Fixed issue where zero-scaled components would get their render state dirty called every time UE::MovieScene::SetComponentTransform is called.

• Fix for when an animation instance is a post process anim instance that is being evaluated we would fail to verify if it has changed because we don't check that it is post process. This marks the sequence as dirty and triggers the spawning phase to happen every frame. Now we validate against post process animbps as well.

• UAF Root Motion Extraction fix Move the same checks we do in the old code regarding 'Force Lock Root Bone' to allow root motion to still be extracted.

• Fix various issues where the normalized view did not always draw its curves correctly.

• Fixed visibility system to define implicit prerequisites only for the CDO. Additionally FSystemDependencyGraph::MakeRelationship only increments serial number if an edge was truly added to safeguard against situations where MakeRelationship gets called for the global dependency graph outside CDOs.

• Fix an issue where some curve types failed to draw the curve line before the first visible key correctly.

• Cine Camera: The Sensor Aspect Ratio is no longer animatable since its value is derived from Sensor Width and Height.

Skeletal Editing

New:

• Skeletal Mesh Editor

  • Explicit Asset Save action also applies pending changes to the asset before saving to disk.

  • Ported Bake Vertex Color tool from Modeling Mode.

  • Changing from one tool to another no longer requires pressing the accept button, multiple tool changes are cached and bulk committed only when users explicitly press apply changes to asset.

  • Added various menu options in the Morph Target Viewer to edit and manage morph targets, including mirror/flip/merge/apply current weight and several others.

  • Added geometry selection support for Morph Target editing, which allows for vertex level transform, soft selection and geometry isolation.

  • Added support for bone weight locking to Edit Skin Weights Tool.

  • The Skeletal Mesh Editor now shows a linear color ramp instead of an array of colors.

  • The Skeletal Mesh Editor now has a dedicated menu in the asset editor viewport toolbar.

• Skeletal Mesh Morph Target Editing Tools

  • Added Mask Morph Target Tool, which applies a custom mask to the editing morph target.

  • Improved Move brush in Sculpt Morph Target tool such that it is non-accumulating and easier to control.

• Improve copy-pasting and duplicating bones.

  • Add new options to Paste Local and Paste Global.

  • Pasting bones now retains the hierarchy of pasted bones.

  • Pasting bones now pastes copied bones and their children.

  • Duplicate now retains the hierarchy of duplicated bones.

• Added Dataflow based workflow to reimport a skeletal mesh from mesh and preserving all existing attribute and morph targets.

• Added a Dataflow Template for Skeletal mesh that takes a static mesh, split it by its mesh islands and convert it to a skeletal mesh where each mesh island is rigidly skinned to a separate bone.

• Skeletal Mesh Modeling Tool: Added "Import Bones from Assigned Skeleton" menu option to Edit Skeleton Tool.

• Added two Dataflow templates for skeletal meshes : Skeletonizer and Subdivision.

• New hotkey Alt-B to toggle draw bones.

• Add Dataflow support for Skeletal mesh asset.

• Skeletal Mesh Modeling Tools: Added support for cotan edge weighting in Edit Skin Weights tool.

• Skeletal Mesh Editor and Modeling Mode: A new version of the paint maps tool is enabled by default, to revert to the old version, use cvar "ModelingTools.UseExperimentalMeshAttributePaintTool 0" and re-enter the editor mode.

• Ctrl-clicking the selection mode buttons in the skin weight tool now converts selection from one mode to another.

• Mirroring now replaces strings from the right, finds strings anywhere in the name and supports regular expressions.

• Added a Clear() method to USkeletalMesh, to help prepare a USkeletalMesh for re-use w/ entirely new mesh/skeleton/etc data.

• Added Blueprint functions to selectively remove morph targets and skin weight profiles from a skeletal mesh.

• Orient bones now orients bones with multiple children in parent orientation.

• Switching between the isolated and the full mesh no longer clears the selection when editing weights.

• Selecting in the list of weighted Bones in the Weight Tool now selects the Bone in the Skeleton Tree.

• Improve selecting affected vertices of a Bone when Shift- or Ctrl-clicking the Affected button when editing Weights.

  • Fix Shift- and Ctrl-clicking Affected sometimes had no effect.

  • Ctrl-clicking Affected now toggles the selection of the affected vertices of a bone.

• Mirror and Orient no longer show an obsolete none axis option.

Bug Fix:

• Skeletal Mesh Modeling Tools

  • Add accumulation support for Relax brush in Edit Skin Weights tool and Paint Maps tool.

  • Fixed data loss when making skin weight edits to vertices holding 12 bone influences.

• Clear stale thumbnail scenes on asset reload.

• Avoid crashing when skeletal mesh reference skeleton changes by invalidating mesh linkup cache.

• Skeletal Mesh Editor: Fixed add support for previewing morph target curves in addition to bone pose in skeletal mesh editor when using the "Running Instance" preview controller in preview scene settings.

• Fix a crash where transient meshes with no mesh description are opened.

• Skeleton tree views now retain their selection and expansion state after edits.

• Bones are now mirrored in global space instead of the first parent's space.

• Collapsing nodes in the skeleton tree no longer deselects children of the collapsed node.

• Fix an issue where the wrong bone was renamed when a name was committed by changing the selection and losing focus.

Audio

New:

• Waveform Editor

  • Playhead refactor to use frame positions to allow better precision, along with handling offscreen playhead positions. Playhead is not rendered when offscreen.

  • Snap to zero crossing shortcut Integrated from 39.00.

• Sequencer

  • Update audio sections to not auto expand to keyframes.

  • Control bus mix track.

  • Audio control bus track.

• Adding db and Decibels to DefaultEngine.ini so it's possible to use UProperty markup for Units.

• Unclamping the "VolumeBase" metasound input for both oneshot and looping metasounds exposed to UEFN.

  • Tooltip reads as "[-60, 12] - Base volume applied to the sound, in decibels. The default value of [0] results in no volume change. A value of [-60] results in silence. [12] is the maximum gain we can apply."

  • VolumeBase default input range now reflects the new clamp range.

  • The clamped range is now [-60, 12] to match the clamp of audio devices. Previously was [-60,0] Updated tooltip to reflect this change in clamp.

• Unified property UX across Attenuation, AudioBus Sends, and Submix Sends.

• Submixes are now ref-counted when using the register/unregister API. When no longer referenced, submixes will be removed from the root. This can be disabled by setting au.RemoveSubmixesFromRoot to 0.

• Movie Render Queue: Expand ability to choose submix to export.

• Added option in CommonButtonGroupBase to suppress button sounds when calling SelectNextButton or SelectPreviousButton.

• Subtitles: Enable resizing of subtitle sections in sequencer.

• Unified property UX across USoundBase/USoundWave/USoundCue/UMetaSoundSource.

Bug Fix:

• Animation Editor

  • Animation Editor and Level Editor Viewports now call UpdateAudioListener when they receive focus and when the perspective camera moves. The Animation Editor has an additional call when we focus on the preview mesh. This fixes the requirement to move the camera in the viewport editor before the audio listener position updates.

  • Animation Editor windows request a new Audio Device so that we don't share the same Audio Device with Level Viewports.

• Sequencer

  • Fix for input channels not resetting when a metasound is changed.

  • Fix MRQ non realtime render to render silence instead of disabling.

  • Fixed sequencer audio channel inputs updating when modifying a metasound asset.

• Disabling Hardware Convolution Reverb on PS5.

• Add CQTest coverage for SoundFieldRendering encode/decode/rotation.

  • New SoundFieldDecoderTests.cpp with 22 test methods across 6 test classes.

  • Tests FAmbisonicsSoundfieldBuffer (construction, reset, duplicate).

  • Tests FAmbisonicsSoundfieldSettings (unique ID, duplicate).

  • Tests FSoundFieldDecoder with both omnidirectional and directional FOA inputs.

  • Tests directional decode correctness: Verifies spatial energy distribution matches source azimuth for stereo and quad speaker layouts.

  • Tests FOA rotation: Energy preservation, W-channel invariance, Y/X channel shifting under yaw rotation, and decoded balance shift after bed rotation.

  • Tests FSoundFieldEncoder channel counts (FOA/2nd order) and directional content.

  • Tests encode/decode roundtrip: Energy preservation, directional bias retention, and silence passthrough.

  • Tests public API: Format name and default settings.

  • Updated AudioCQTests.Build.cs to add SoundFieldRendering and AudioExtensions module dependencies.

• Waveform Editor

  • Fix for waveform editor playhead snapping to proper trim start or end bounds when editing

  • Fix playhead snapping when editing trims to snap to appropriate trim start or end bounds.

  • Fixed an issue in the Waveform Editor where wave files containing a partial final sample block were loaded with invalid trailing bytes, causing corrupted playback. The invalid bytes are now silently truncated at load time — the raw asset data is not modified.

• Fix for MRQ to render silence when there is no audio to allow timing of sequences to line up

Architecture

New:

• Change SubmixEffectReverb default Gain from 0.0 to 1.0 for new assets.

• Adding optional Low pass and High pass filters to submix and audio bus sends.

Bug Fix:

• Fixed issue where SoundBase→bEnableSubmixSends being false would ignore attenuation submix sends.

• Crossfade dry signal against submix effect chain overrides when no base chain absorbs the gap.

• Fix FDelay incorrect output for sub-1-sample delays.

• Fix potential thread-safety races in vorbis DLL init and AudioFormatOgg singleton.

Deprecated:

• FSoundWaveProxy now acts as a broker for FSoundWaveData so consumers can optionally update to latest data (i.e. post asset re-import). This requires the deprecation of FSoundWaveProxy that was just forwarding calls to the FSoundWaveData.

MetaSounds

New:

• Adds the experimental MetaSound Channel Agnostic Types (CAT) Wave Player node and its supporting types under the MetasoundExperimental plugin.

  • Engine runtime

    • UCatSoundWaveContainer + FCatSoundWaveContainerEntry: a UObject container of weighted USoundWave entries, edit-time UI for designers.

    • FCatSoundWaveContainerProxy / FCatSoundWaveContainerData: audio- thread proxy snapshot of the container, doubles as Audio::ISoundWaveContainer.

    • Audio::TCatProxyView: lock-free linked-list base for the proxy, supports mid-render hot-swap of container state from the game thread to the audio render thread.

    • MetasoundCatExperimental::FSoundWaveContainerAsset: MetaSound data- type wrapper held by value on the audio thread; namespace-scoped to avoid collision with the Polyphony plugin's same-named asset type.

    • MetasoundCatWavePlayerNode: polyphonic Audio Wave Player. Outputs a polymorphic CAT audio reference resolved at bind time per the Format / Auto / SourceAuto chooser. Configurable max voices, Index / Sequence playback types, Standard / Random playback modes. Sequence mode supports start index, finite/infinite loops, and reset trigger plus per-stage trigger outputs. Random mode supports weighted selection, deterministic seed, and an avoid-recent-N window. Pitch shift via plain float input pin.

  • Editor

    • AssetDefinition_CatSoundWaveContainer + factory: New-asset and "Create Sound Wave Container" content-browser context menu on SoundWave selections.

    • Editor module wires the MetaSound graph-pin factory registration for the new data type. MetaSound Engine / Frontend prerequisite edits.

    • UMetaSoundSource::CalculateAutoSourceFormat: rewrite to walk RuntimeInputData parameters with InParams overrides and pick the greatest channel count among Object / ObjectArray inputs. Adds a checkf guard requiring RuntimeInputData to be cached before the call. Intentional behavior change in scope of this change.

    • MetasoundFrontendSourceInterface: removed the unused AudioMixerNumChannels extern. The API never shipped, so no deprecation shim is required.

• Retain MetaSound input values on presets when parent graph inputs are renamed.

• Make MetaSound preset reset to default use inherited parent values.

• Improvements to the MetaSound node update transform API for C++ node developers New biquad node bandwidth default value for new nodes to avoid DSP edge cases.

• MetaSound DynamicInterfaceNodeConfiguration: Built-in node configuration for sub-interfaces and variants.

  • Add FMetaSoundDynamicInterfaceNodeConfiguration, a generic FMetaSoundFrontendNodeConfiguration that automatically handles sub-interface instance counts and variant type selection based on a node's FClassInterface definition. This eliminates the need for custom per-node configuration structs for nodes that use sub-interfaces or variants.

  • Changes:

    • Add MetasoundDynamicInterfaceNodeConfiguration (Frontend) - core configuration struct that reads FSubInterfaceDescription and variant descriptions from the FClassInterface to drive the node's interface override.

    • Add MetasoundDynamicInterfaceNodeConfigurationCustomization (Editor) - details panel customization providing variant type dropdowns and sub-interface count controls.

    • Update MetasoundExampleWeightedSumNode to use the built-in base configuration, removing the custom FMetaSoundExperimentalExampleWeightedSumNodeConfiguration workaround.

    • Update node registration macros and graph builder for dynamic interface configuration integration.

    • Add engine tests for configuration logic and UI customization.

• Added MetaSound Input Browser for bulk viewing and editing of MetaSound input values.

• MetaSounds that are sent a StartTime input parameter but do not implement the UE.Source.StartTime interface will now only warn once instead of on every play.

• Native MetaSound nodes can define a custom icon and color.

• Enable relative render cost by default Add cvar for logging a sound's relative render cost exceeding a threshold.

• Add MetaSound asset action for fixing up duplicate class name issues.

• Improved MetaSound builder Blueprint API and editor builder listener support for pages.

• Added various options for easy node creation when dragging assets into the MetaSound editor.

Bug Fix:

• Fix MetaSound input widget settings getting overridden when set to a type other than editor preference default.

• Fix crash when au.MetaSound.Experimental.OperatorPool.SetMaxNumOperators is set via Console Variables: In *.ini.

  • The cvar was registered as an FAutoConsoleCommand, but Console Variables: ini parsing creates placeholder IConsoleVariables for any name it encounters. When the MetasoundGenerator plugin later registered the command with the same name, FConsoleManager::AddConsoleObject hit a fatal log: 'Console object named... can'\''t be replaced with the new one of different type!'

  • Convert the registration to a TAutoConsoleVariable, default -1 (leave the pool default unchanged). An OnChanged callback forwards the value into the operator pool. StartupModule applies the current cvar value once the pool exists, so values set from the ini before the module loads still take effect.

• Fix AD Envelope attack phase skipped when Attack Time driven by Value (Float) node with Init Value of 0.

• Fix AB/BA potential deadlock between FOperatorPool::CriticalSection and OnAudioDeviceDestroyed.

• Make trigger repeat node high precision so it doesn't drift compared to Quartz / DAWs.

• Fix MetaSound preset input nodes not respecting sort order.

• Fix crash when setting a MetaSound constructor input or output to an unsupported type (ex. Trigger).

• Fix editor display issues when renaming MetaSound inputs or outputs.

• Fix ensure when reloading MetaSound externally added and referenced by another asset.

• Fix MetaSound patch details panel showing blank output format row.

Sequencer

New:

• Audio Sequencer

  • Added a "Play Until Finished" option to Audio Sections in Sequencer. When enabled, the section's evaluation range extends past its visual end to the sound's natural duration, keeping volume and pitch keyframes, pause, and state-restore cleanup active throughout the tail. Enable it with the CVar Sequencer.Audio.UsePlayUntilFinished (defaults to off).

    • Note: Trimming or resizing a section to a shorter length automatically disables the option, SoundCues that contain Random or Branch nodes are not supported, and MetaSounds extend to the sequence's playback-range end and stop via their OnFinished callback.

  • Added a bRepeating property to UMovieSceneAudioSection to replace the semantically overloaded bLooping property. The new property accurately describes Sequencer behavior by restarting a one-shot sound at the section boundary when the section is longer than the sound, reserving the term “looping” for natively looping audio assets. The transition is controlled by the Sequencer.Audio.UseRepeating CVar (enabled by default), and existing assets are migrated automatically on load.

  • Fixed a bug where loop-divider lines in the Sequencer timeline stayed at their original screen positions instead of moving with the audio section when it was dragged.

  • Fixed an issue where audio sections defaulted to looping when added to a sequence, regardless of the source sound asset's loop setting. Audio sections now initialize their loop state from the source asset.

• Batch editing and highlighting for stale actors in audio sections when right clicking on track to batch edit, or multi selecting audio sections. Enable highlighting with cvar au.OutlineAudioActorAttachments.

Bug Fix:

• Fixed a bug where audio sections with a number of float parameter inputs that was an exact multiple of 9 silently dropped all float input data at runtime. Affected sections appeared to play correctly but none of their float parameter automation took effect.

Subtitles

New:

• Waves with Subtitles attached as UserData will now automatically play and stop their subtitles when the Waves are played from inside another Wave, such as a MetaSound or SoundCue.

• When scrubbing through a Sequence with subtitles, the subtitles will now display in the editor viewport.

• Sequencer Subtitle sections initialized with a blank subtitle are now given a default duration of 3 seconds.

• The Subtitles plugin will now warn if you try to replace the UMG widget with an invalid or missing asset.

• Added an optional Border UI element to subtitle UMG widgets' TextBlocks.

• SRT/SubripText files can now be used for bulk Subtitle import. A freshly-imported SRT file will create a Basic Overlay asset, which can be right-clicked to select Convert Basic Overlays To Subtitles.

Bug Fix:

• When loading a Subtitle asset in the editor, it will now enable/disable editing its Duration parameters based on its DurationType.

WaveForm

New:

• Waveform Editor

  • Changing the Fade handle icons and making the colors more colorblind friendly.

  • Decoupled fade in and fade out from the trim transformation. Fade behavior is now controlled by a standalone UWaveformTransformationFade sub-object on UWaveformTransformationTrimFade, making fades configurable independently of trimming in the Waveform Editor.

Bug Fix:

• Waveform Editor

  • Fixed an issue where pressing Shift+Space to return the playhead to the start of a waveform did not reset the playback start position, causing the next playback to begin from a stale offset instead of the beginning of the active region.

  • Fix crash when deleting an open SoundWave asset with the editor open/minimized. Guard USoundWave modification in ~FWaveformEditor() when the editor is closed due to asset deletion.

  • Sound Wave: Fixed an issue where opening a Sound Wave asset in the Waveform Editor while the asset was playing in the editor stopped playback. Transformation edits now take a targeted path in USoundWave::PostEditChangeProperty() that rebuilds compressed data without freeing audio resources for in-flight sounds.

  • U Sound Wave: Adding LUFs and PeakLoudness to metadata in the content browser. When the Waveform Editor is enabled, audio analysis is triggered in 3 spots:

    • On asset import/reimport (per asset).

    • When opening an asset in the Waveform Editor (per asset).

    • Using the ResaveSoundWaveLoudness commandlet.

Editor

New:

• PCG

  • Moved UPCGManagedResource management out of UPCGComponent and into FPCGManagedResourceContainer.

    • Reduces code duplication for new execution source types.

  • PCG Builder Volume.

    • Editor only actor used to limit the bounds of generation when using the PCG Builder commandlet.

  • Blueprint : Point loop functions can require game thread execution (single threaded).

    • This will cause errors if the Blueprint element itself is not 'bRequiresGameThread'

  • PCGGraphExecutionRegistry

    • Now possible to register execution source providers through a common registry.

    • Use this registry to gather execution sources to display in Graph debugger.

    • Implement a default provider for UPCGComponent and UPCGDefaultExecutionSource.

  • More work to move from UPCGComponent to IPCGGraphExecutionSource.

    • FPCGActorComponentMapping renamed to FPCGTrackingManager.

    • Move most of the API to IPCGGraphExecutionSource except for partitioning.

    • IPCGGraphExecutionState already supports partitioning in its interface but actual implementation is still very much APartitionActor dependant (needs to be abstracted away).

    • Some of the partitioning API was moved to IPCGGraphExecutionSource but implementers should not expect functional tracking for anything other than PCGComponents.

• Added a batch processor framework for running functions on large datasets - typically of assets.

  • Results will be written to Saved/MultiprocessResults/results.txt, the location of results can be overridden with the `-resultsfile=` option. -numworkers= can be used to control the number of workers used to process the batch.

  • The Batch Process facilitates parallelism which is useful when invoking a function a large number of times (e.g. tens of thousands or millions). Batch jobs can also be started from script using `BatchProcessLibrary::RunBatch`.

  • Here's a complete example in python - note the final steps regarding registration ceremony:

    Python

    # Save in /Game/Content/Python/snapshot_assets.py import json import os import unreal # Declare a uclass with a function that we want to run, this simple function just # takes an asset path, loads it, stringifies it, and writes the string to a file: @unreal.uclass() class SnapshotAsset(unreal.Object): @unreal.ufunction(params=[str]) def snapshot_asset(self, asset_path: str) → None: # Load the asset: asset = unreal.load_asset(asset_path) if asset is None: unreal.log_error(f"FAIL: {asset_path} (asset not found)") return json_str = unreal.JsonObjectGraphFunctionLibrary.stringify([asset.get_package()], unreal.JsonStringifyOptions(unreal.JsonStringifyFlags.FILTER_EDITOR_ONLY_DATA)) # Build a nested output path from the package path, stripping the leading '/'. # e.g. "/Game/Baz/Foo" → "Game/Baz/Foo.json" and write to that file: relative = asset_path.lstrip("/") out_path = os.path.join(unreal.Paths.project_saved_dir(), "SnapshotAsset", f"{relative}.json") os.makedirs(os.path.dirname(out_path), exist_ok=True) # Write out the stringified asset: with open(out_path, "w", encoding="utf-8") as f: f.write(json_str) unreal.log(f"PASS: {asset_path} → {out_path}") # Discover all assets of the specified type, run snapshot_asset def _run_snapshot(asset_class: str)→ None: registry = unreal.AssetRegistryHelpers.get_asset_registry() registry.wait_for_completion() asset_filter = unreal.ARFilter(class_names=[asset_class], recursive_paths=True, recursive_classes=True) asset_paths = [str(a.package_name) for a in registry.get_assets(asset_filter)] # Build the job description. job = { "function": "/Game/Python/snapshot_assets_PY.SnapshotAsset:snapshot_asset", "arguments": [{"asset_path": p} for p in asset_paths], } # Run the batch — blocks until all jobs complete. results_json = unreal.BatchProcessLibrary.run_batch(json.dumps(job), num_workers=8) results = json.loads(results_json) passed = [r for r in results if r["Passed"]] failed = [r for r in results if not r["Passed"]] print(f"{len(passed)}/{len(results)} passed") for r in failed: print(f" FAIL: {r['ArgumentSummary']}\n {r['Output']}") def run_blueprints_snapshot() → None: _run_snapshot("Blueprint") if __name__ == '__main__': # critical, prevents forkbomb if init_unreal is used to import this script run_blueprints_snapshot()

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  • The final step is to register the SnapshotAsset class with Unreal Engine. Typically this is done by adding `import snapshot_assets` to your project's init_unreal.py. Once that is complete you can run the script like any other python script:

    Command Line

    UnrealEditor.exe "D:\Path\To\Your\ProjectName.uproject" -run=pythonscript -script="D:\Path\To\Your\Project\Content\Python\snapshot_assets.py"

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  • To launch a batch job from the command line use: `UnrealEditor ProjectName -run=BatchProcessCommandlet D:\Path\To\Jobs.json` where Jobs.json describes a function and list of arguments to invoke said function with, e.g.:

    Shell

    { "function": "/Script/Engine.KismetSystemLibrary:PrintString", "arguments": [ { "InString": "Hello World", "bPrintToLog": true }, { "InString": "Hello World2", "bPrintToLog": true } ] }

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• Added reset to default support for root properties of Editor Preferences, Project Settings, Keyboard shortcuts.

  • Added default value in the tooltip of the property/keybind name.

  • Added CVAR to refresh cached default values : SettingsEditor.ClearObjectDefaultPropertyValuesCache.

  • Limitations are the following:

  • It will not work for properties that are missing the Config specifier.

  • It will not work for custom added rows obviously.

  • It will not work for settings object with a customization since it overrides the default one.

  • It will not work on nested properties, only the root properties of a settings object are supported for performance to avoid having to parse the default stringify value recursively.

• Added ability to search for CVAR, KEYBIND, CONTEXT in Editor, Project, Input Settings.

  • Added keybind button to start listening for key presses and search for these input chords.

  • Simplifying editor settings keybind list by removing description based on command tooltip, description is available in the tooltip now.

• Added behavior selection for tabs navigation action in Editor Settings / Misc, before this change editor only navigates between assets and uses last access time to determine order, now browser style tab navigation is available, it uses window tab order (default is browser style behavior) CTRL+Tab goes forward, CTRL+SHIFT+Tab goes backward.

  • Added an option to hide tab navigation popup dialog widget and directly perform the action (default is showing this dialog).

  • Before this change navigation only worked on asset tabs, you can now navigate between any tabs (editor settings, project settings, logs...).

  • Reduced size of items in tab navigation dialog widget.

  • Fixed Scrollbar not working and Listview not scrolling into view.

• Added UnrealAssetStringify: A standalone program to quickly print a.uasset or.umap to json. Use Engine\Source\Programs\UnrealAssetStringify\BuildScripts\UnrealAssetStringifyInstall.bat to build the tool and optionally associate it with the asset diff command in p4v. Once built the tool can be found at Engine\Binaries\${PLATFORM}\UnrealAssetStringify[.exe] Example usage:

  • `UnrealAssetStringify.exe "D:\Path\To\A.uasset"`: Prints the asset to stdout.

  • `UnrealAssetStringify.exe --save "D:\Path\To\A.uasset"`: Writes the json to Engine\Programs\UnrealAssetStringify\Saved

  • `UnrealAssetStringify.exe --save="D:\Output\A.json" "D:\Path\To\A.uasset"`: Writes the json to "D:\Output\A.json" instead of the default save location.

  • To open a.uasset for viewing in vs code use Engine\Source\Programs\UnrealAssetStringify\Scripts\UnrealAssetStringifyOpenAsset.bat.

  • To manually diff uassets using p4v use Engine\Source\Programs\UnrealAssetStringify\Scripts\UnrealAssetStringifyP4VDiff.py.

    • UnrealAssetStringify is a read-only tool that is useful for reviewing asset changes, post mortem analysis, and asset content indexing; it cannot be used to update uassets.

• Added copy all info to clipboard in project badge context menu.

• Improved material editor preview mesh material slot picker to persist user choice in config, default is material slot 0 active.

• Migrated some common reference validation logic to UAssetReferencingPolicySubsystem::ValidateAssetReferences It now supports:

  • Denoting whether a missing reference is actually missing or only unsaved.

  • Optionally also validating references to C++ modules in plugins (when 'AssetReferencingPolicy.CheckForIllegalCppRefs' is enabled).

  • Ignoring missing references from a redirector, as they may redirect to unloaded plugins.

• Promoted "Slate.bAllowThrottling" to Editor Preferences, which allows real-time property edits when disabled.

• Make the "open source code" action async, so that the editor doesn't lock up every time you press it and wait for your IDE to open.

• Downgraded error handling when a console variable was not found from fatal to error in DeveloperSettings::ImportConsoleVariableValues.

• Added new grid floor material to newly created profile and engine profile as long as they don't have the floor material overridden.

• Change the IOS preview options in order to mirror Android preview.

• Added command with keyboard shortcut to Capture Thumbnail for asset in the Content Browser (CTRL+SHIFT+T).

• Rename ToggleFeatureLevelPreview to TogglePreviewPlatform Rename IsFeatureLevelPreviewEnabled to IsPreviewPlatformEnabled Rename IsFeatureLevelPreviewActive to IsPreviewPlatformActive.

• Merged ToggleFeatureLevelPreview into SetPreviewPlatform using a new bCompileShaders parameter that controls whether or not we compile the shaders.

  • Added bRestore parameter to device profile update to skip redundant RestorePreviewDeviceProfile during toggle.

  • Removed CachedEditorShaderPlatform member, using GMaxRHIShaderPlatform directly.

  • Removed toggle button restriction for GMaxRHIFeatureLevel.

• Added in-editor validation for missing hard-refs This is disabled by default, but can be enabled by setting the CVar 'AssetReferencingPolicy.CheckForMissingHardRefs' to true.

• Editor Preview Platform Optimizations Materials are already updated by SetPreviewPlatform, so disable the automatic per-texture material dependency update 8min →1min Preview transition.

• Improved support for incremental validation in incremental cooks.

  • Incremental cooks already mostly handle incremental validation, as they skip loading the package if it hasn't changed (as validation runs via UCookOnTheFlyServer::LoadPackageInQueue), however changes to a world would still validate all their external objects. This can be quite slow for large worlds.

  • This change improves the incremental validation support so that it only validates the specific external objects that have changed in a world being re-cooked. It does this by comparing the hash of each external actor object against the previous version that was validated, and skipping any that haven't changed.

  • This feature is disabled by default, but can be enabled by setting the CVar 'cook.validation.IncrementalExternalPackageValidationEnabled' to true.

  • Note: It only currently works for single-process by-the-book cooks. You can also now trigger a full revalidation when running incremental validation against a new build version, by setting the CVar 'cook.validation.IncrementalValidationRequiresSameBuildVersion' to true. This is disabled by default.

• Added ConfigureCookSession event, to allow registering extra artifacts and collectors to be used by the cooker.

• Fixed level editor PlayFromHere action not working with keybinds (set to ALT+SHIFT+P).

  • Improved API to play from here based on click, selected actor or custom position.

  • Play mode (Floating window or in viewport) will be based on the selected user choice in Play Settings.

  • Play from here will first check selected actor (must set bCanPlayFromHere to true) then fallback to viewport last clicked location.

• Selection: Typed Element Common actions now supports a CanDuplicate so asset editors can customize if they allow for duplicating of the selection.

• Add support for capturing expansion state per custom built details view via ViewIdentifier's.

  • Initial usage example in SStateCentricViewMainStateNode.cpp.

• Scene viewports can now compute correct mouse positions in cases where the underlying scene render is a different resolution from the Slate output of the viewport.

• Make "new-process" PIE work like "Preview Platform"

  • Mobile "new-process" PIE now respects the Preview Platform set, the Device Profile and the Aspect ratio(flipped, unflipped) of the main editor viewport.

• Add Aspect Ratio to IOS Preview Json.

• Revision Control: Revision control helpers get status functions can now use the cached file state. This can be useful after operations that already update file state (i.e. saving files).

• Minor Improvement of Log Categories performance in the OutputLog.

• Add Preview json Versioning.

• Add Flip Aspect Ratio for Preview Json.

• Add ConfigRules to Android Preview Json Clean-up unnecessary usage of FName in AndroidDeviceSelector.

• Preview Json Improvements.

  • Added IosPreviewDeviceProfileSelectorModule in order to enable Generate/Preview Json on IOS.

  • The DeviceSelectors will now return the PreviewPlatform from the DeviceProfile selected and the device properties.

  • Modified the way the Preview Json preview platform label name is shown. It now displays Preview Platform Name + Device Profile, instead of just Device profile.

  • Confirmation Dialog added when Generating Platform Json.

• Add Editor Settings to configure default name with prefix and suffix for new assets.

• Added shaderball as a mesh preview in the material editor.

  • Save the last used preview mesh in config to load it again on material and material instance editor opening.

  • Materials will use their own preview mesh property if set, otherwise fallback on the last used editor preview mesh, when the last used preview mesh can't be loaded, falling back to the sphere mesh.

• Added keybind to toggle the grid in Asset Editor (ALT+SHIFT+G since ALT+G is used for perspective view and G is used for GameView).

• Add Control + Shift + Z as an alternate InputChord for Redo.

• Cook-time validation improvements.

  • Pre-load external objects prior to running validators. This is controlled by the CVar 'DataValidation.LoadExternalObjectsForCookValidation' and is enabled by default to match the default editor behavior.

  • Added support for reporting the total validation duration per-validator for cook-time validation. This is controlled by the CVar 'DataValidation.ReportCookValidationStats' and is enabled by default.

• TextureFormatOodle is now a built-in Engine Module instead of a Plugin. It is used for texture encoding by default, regardless of config, even in no-Plugin minimal configurations. The only NVTT and ISPC fallback codecs are now deprecated.

• DataTable export struct to string and file as objects.

• Added more level of precision to editor spinboxes.

  • Shift = Deca (+10/-10)

  • Ctrl = Deci (+0.1/-0.1)

  • Shift + Alt = Hecto (+100/-100)

  • Ctrl + Alt = Centi (+0.01/-0.01)

• Added editor project badge context menu with the ability to copy info to clipboard (project name, version, changelist, branch, build configuration, build date, RHI).

  • Added double click to project badge will copy changelist to clipboard (for QA).

• Added Keyboard Shortcut menu entry in Edit menu.

  • Added Keybinds to access Editor, Project, Keyboard preferences directly.

• Extend "Browse to Asset" capability for Editor Utility Widget.

  • Allow tab context menu actions without activating the tab (web browser style).

• Display ticked objects in ActorPalette viewport, when realtime toggle is enabled.

• Data Validation: The Data Validation Commandlet has been refactored to make custom behaviors via a child class implementation easier to do.

• Add GetPreviewPlatformName Blueprint function.

• Improved ortho view grid density logic when in a mode where view background is irrelevant.

• Data Registry: Fixed "Find Row References" to view references with type FDataRegistryId::StaticStruct() using the name from FDataRegistryId.ToString().

• Add support for filtering shown categories when creating a details view. Add support for hiding headers when creating a details view.

• Added Filter by Selection capability in Content Browser and AssetPicker with keybind ALT+F, it uses the active selection in the context to set filters.

• Added the ability to display specific RGBA color channels in the active editor viewports, as well as options to control how the alpha channel specifically is displayed. These options show up under the View Mode dropdown of the viewport toolbar.

• Added support for -RpcClientNum to handle multiple clients with unique ports, and they just increment after the "client" port in the.ini, when using -RpcConfig=foo.

  • Added support for multiple listening ports for Rpcs.

• Improved BP Editor's menu filtering with additional context options for show flags and view modes and camera settings.

  • Fixed cannot set camera clipping settings in the BP Editor's viewport.

  • Fixed cannot set other show flags in the BP Editor's viewport.

• Allow Abstract classes Tagged Asset Browser Filter Allow Tagged Asset Browser searching for NativeParentClass Allow Tagged Asset Browser searching for Skeleton.

Bug Fix:

• Property Editor

  • Fix struct array elements sharing expansion state after ForceRefresh.

  • Fix struct UPROPERTY rows losing expansion state across ForceRefresh.

• PCG

  • Fix UPCGPointArrayData::GetTransformCopy not respecting inheritance.

    • Revert collapse to use GetTransformCopy again now that it is fixed.

  • PIE: Load as preview fix for managed components.

• glTF Exporter

  • Supporting better primitive number calculations, supporting exports for meshes with unused Materials.

  • Out of bounds crash 'fix' for SourceModel export.

• Fix BroadcastBeginObjectMovement/BroadcastEndObjectMovement pairing on click-only gizmo interaction. GEditor→BroadcastBeginObjectMovement was fired unconditionally in GizmoManipulationStarted, but the matching BroadcastEndObjectMovement was gated behind an early-return that only fires for actual drags. Clicking a gizmo handle without dragging left any listener of OnBeginObjectMovement/OnEndObjectMovement with a permanently-stuck is-moving state until the editor restarted. This was breaking root motion being applied to actors in the anim mixer, causing them to stop responding to root motion until another drag of the gizmo is attempted.

• Scene Viewport: Fix issue when transitioning from the software cursor to the hardware cursor where clamping the cursor position: 1) incorrectly applied pixel scale resulting in incorrect positions; and 2) subsequent mouse movement updates caused a disconnect between the normal and unbounded cursor position.

• Fixed ability to copy a property without any reference = "None" to clipboard to be able to paste it later in a details view row.

  • Fixed show flash animation on copy/paste when using context menu with custom actions.

• Fixed blank project that fail to Quick Launch on Android devices with a Binary build.

• ITF: Fixed some editor input freezing during static mesh async builds. In detail: Moved InteractiveToolsContext invalidation propagation out of throttle-gated Tick into a separate hook called before the viewport tick gate, so input-driven invalidations reach bNeedsRedraw during async asset compilation.

• Fixed an issue that would wipe out instanced struct data when using JSON import and export of Data Tables.

• Change world leak check in the editor to ensure instead of crashing, this fixes issues when transferring maps in Play in Editor with certain editor windows open.

• Fix crash in Editor texture viewer due to preview platforms texture encodings when some platforms were not fully installed on the client system.

• ResavePackagesCommandlet now loads default editor modules, which gives them a chance to bind to UPackage::OnTransferMetadataRequested. If the callbacks aren't bound, data stored in FMetaData is thrown out upon resave.

• User Asset Tags: Fixed ResavePackagesCommandlet discarding User Asset Tags on resave due to UserAssetTagsEditor module not being loaded (metadata transfer wasn't bound).

• Fixed crash saving levels with high actor counts.

• Fixed content browser deleting folders with multiple assets contained in the same package would fail since there is a mismatch between assets count and loaded objects.

• Fixed Launcher process and thread leaks, and memory corruption.

• Fixed color picker would close and not transact any property change on any Blueprint classes, this is caused by the Blueprint rerun construction script and objects replacement happening in editor, the actor and its sub-objects are duplicated and replaced after a property change (value set), this would trigger a details panel refresh with the new objects and underlying property handle would change, old ones would be invalidated, and color picker would close immediately without processing transaction. This would not happen with C++ actor class since they are not getting replaced.

• Fixed Editor Preferences: General Appearance application scale not updated after an import.

• Fixed recursive call to FTargetPlatformManagerModule::ModulesChangesCallback during post Turnkey installation that causes a dead lock.

• Fixed external environment variable changes during turnkey.

• Skipped hit proxy invalidation when the user is controlling a viewport piloted camera, to minimize flush performance cost.

• Fixed pressing a keybind like DELETE in content browser when nothing is selected would still trigger the command for the outliner selection even if it does not have the focus.

  • Added option in editor preferences to hide/show quick jump text (red/blue text) in the bottom right of the content browser (hidden by default).

• Fixed tab location not saved and preserved for assets using workspace editor.

• Fixed General Appearance - Editor Preference : Import values are not saved.

• Modes - Gizmos: Update default mode manager implementation to use the asset editor default mode, and the level editor one uses the level editor default ed mode.

  • Removed swapping of modes - this wasn't having an effect on gizmo visibility in asset editors.

  • This fixes an issue where when legacy gizmos are toggled on globally, a selection must be active in the level editor for the gizmos to display in an asset editor that was using the default editor modes.

• Fix Preview crash caused by copying over Flags when Platforms Cvar copy.

• Give the RenderDoc, PixWin, and Xcode "CaptureFrame" toolbar entries each their own unique id.

• Fixed restore open asset tab location on restart (docked or undocked) after a crash.

• Fix Preview Platform in Editor could fail to show the textures with updated LOD settings for the chosen platform.

• Fix VT thumbnails could appear too bright due to SRGB flag mismatch.

• Fixed an issue where the Recently Executed Python Files menu included files that were run during editor startup.

• Fixed configuration import by removing irrelevant sections for keybinds to avoid same section+key clash on merge.

  • Fixed configuration export by allowing duplicated keys in a section when merging files, this was causing keybinds to be lost.

  • Added notification hyperlink to navigate to exported file.

• Selection: Fix a couple of crashes with ISM selection, and improve the traversal of actor, component, ISM with double clicks.

• Fixed crash caused by the NotifyToolsOfObjectReplacement event being triggered on garbage collected assets.

• Fixed ensure in CurveTableEditor when deleting a curve row.

• Fixed memory leak in content browser when removing collection.

• Fixed logging being delayed by 2 logs calling UAT with the Launcher.

• Fixed possible crash when trying to open a new map.

• Data Validation: Fixed an issue where the data validation fixers wouldn't always capture all the modified packages during the validation.

• Fixed Scene Outliner base selection is lost when ctrl is held and a new search is made to select additional elements in the scene outliner.

• Fix content browser favorites being lost when unmounting plugins.

• Geometry Mode: Fixed erroneous usage of StaticClass in ShutdownModule.

• Asset Rename Manager: Avoid reporting references from sub-objects of redirected path.

• Fixed hotkeys do not work in the Outliner when undocked.

• Fix crash when opening color picker during a hitch.

• No longer moves a viewport-locked actor when input is disabled in that viewport.

  • The "picture-in-picture" preview for camera actors could sometimes rotate that actor as if piloted. This was because the viewport's camera controller was clamping the pitch angle to -90;+90 degrees, so when that came into effect, the output pitch differed from the input pitch.

  • This in turn was picked up by the viewport's camera movement handling as a difference that needed to be reproduced on the locked actor, something that happens when piloting an actor using a movement mode that has inertia for smoother movements.

  • This change just disables that part of the code when input is itself disabled (which is the case in the PiP viewports), since it makes little sense to move a locked actor if the user doesn't have input to pilot it.

• Fix an issue on Mac where the traffic buttons showed up on the rename window.

Deprecated:

• Gizmos

  • Remove experimental gizmo option from level editor viewport. This was rehomed to gizmo settings and profiles.

  • Remove outdated and experimental light gizmo plugin. These are no longer good representations of how we build gizmos in the editor, and have outlived their experimental status. We'll re-evaluate their UX in the future. For now, they needed to be manually activated via the mode manager on the level editor, and required for external teams to make code changes in order to use it. If there was usage of this, it can always be restored from the github history in the meantime.

• Deprecate ChangeFeatureLevel/ChangePlatformLevel(ERHIFeatureLevel::Type) on UGroomBindingAsset and UGroomAsset, and HandlePlatformPreviewChanged/HandleFeatureLevelChanged(ERHIFeatureLevel::Type) on UGroomComponent.

  • Replace the two separate cached feature/platform level members into a single EShaderPlatform CachedResourceShaderPlatform.

  • Replace with ChangeShaderPlatform(EShaderPlatform) and HandlePlatformPreviewChanged(EShaderPlatform).

• Deprecate PIEPreviewDeviceProfileSelector Remove all dependencies to the PIEPreviewDeviceProfileSelector from the Engine.

• Deprecation: Remove deprecated AActor::EditorKeyPressed function.

Datasmith

Bug Fix:

• Fix for crash building morph targets with legacy FBX importer when UseT0AsRefPose is set.

• Fix crash when opening Dataprep Asset.

Framework

New:

• TEDS

  • Cooperative Task Refinement

    • Wait a fixed amount of frames (default: 5) when there is no more time left, if the editor doesn't recover use a minimal processing time (default: 2ms).

    • Added additional stats.

  • Added tab to debug tables to the TEDS Debugger.

  • Refactored Query Capability forwarding to use explicit context environments.

  • Added the ability to put the compatibility layer in immediate mode.

  • Added Query Stack nodes that trigger delegates when a change is detected.

  • Added support for dynamic columns to the new query context.

  • Deprecated `CurrentRowHasColumns` and `CurrentBatchTableHasColumns` in favor of `CurrentTableHasColumns`.

  • Added functionality to retrieve the unique tag that's added to a table.

  • Made the actor table derive from the more general UObject table.

  • Context Capability mocks now have an explicit `Assign_*` function and overloaded functions now work by overloading those `Assign_*` functions.

  • Added additional logging to track the state of TEDS Core and Compatibility (de)initialization.

  • Removed ClearRow in the command buffer for a performance gain.

  • Added a new mapping key type "KeyIssue" to report errors. [TEDS] The type of a mapping key can not be retrieved. [TEDS] "GetAs" was added to the mapping key to be able to retrieve the content.

  • Reintroduced the `TEDS.Enable` CVar.

  • Updated the STedsSearchBbox to support the new query search node.

  • Added 2 new nodes to the Query Stack for searching.

  • Added the ability to calculate a hash of the topology of a table. Changes whenever a row/column is added/removed.

  • Marked more columns to searchable and sortable.

  • Added a utility class to collect row handles concurrently from multiple threads.

  • Cooperative task refinement: Exclude its own runtime from calculating the available time next frame.

  • Allow dynamic columns to be declared at compile time.

  • Added `RegisterHierarchies` to the factories to allow hierarchies to be registered on initialization.

  • Simplified Perforce TEDS data interaction.

    • Skein Perforce TEDS data interaction.

• Replaced cvars by RevisionControlOverlaySettings to support the revision control overlay's options.

• ITF Behaviors: Apply the "input complexity is priority" convention to appropriate base ITF behaviors.

  • Moved the binding complexity priority step definitions to FInputCapturePriority.

  • Mapped and active modifiers automatically count towards a behavior's priority. This can be disabled with the "ITF.UseITFWideBindingComplexityPriority 0" CVar.

• Log a warning if an EditCondition involves a property that is marked deprecated.

• Add ability to indent TokenizedMessage(s) when shown in Message Log(s) to allow for semi-visual grouping.

Bug Fix:

• TEDS

  • Fixed incorrect pre-check before calling `AddCompositionToEntity_GetDelta`.

  • Fixed the result counter in FQueryResult not being atomic.

  • Fixed observers on occasion invalidating the list of pending UObjects in TEDS Compatibility. [TEDS] Fixed an off-by-one bug that could loose async loaded actors.

  • Fixed commands getting stuck in the command buffer.

  • Fixed RemoveColumns called from a query callback not being called on rows outside the active query context.

  • Fixed bug in BatchAddRemoveColumns where an assert could trigger if columns were added and removed in the same call.

  • Mapping performance significantly improved at large scale (100k+).

  • Explicitly flushing the command buffer internally when used in a direct API call to provide consistent behavior.

  • Fixed FNames sorted by the appended number instead of the internal ID.

• Moved SccStatusUpdateTags queries out of PerforceSourceControlProvider to RevisionControlProcessors. This ensures proper tag cleanup even when perforce is not used/connected.

• Fixed resave commandlet failing to find any asset when using the asset registry when the package has a path relative to the engine dir.

  • Added -ForceMaterialAutoUsageFlag command line option, to be used in conjunction with -onlymaterials, to force set the corresponding option on all processed materials.

Interchange

New:

• USD Interchange

  • USD Interchange imports will now respect the UseWorldSpaceNormals material parameter that is produced by landscape exports to USD.

  • USD Interchange error handling will now also collect, deduplicate and display USD SDK errors as Interchange errors.

  • Added support for importing Chaos ClothAssets via USD Interchange via dedicated schemas.

  • Added support for skeletal mesh collapsing on USD Interchange imports. It is now possible to individually collapse Mesh prim hierarchies inside SkelRoots as separate SkeletalMeshes, by using the prim kinds and/or collapsing schemas, controlling the USD Translator's collapsing settings, and the Generic Assets Pipeline options for combining skeletal meshes.

  • Removed the extra sprite added to every spawned scene component on USD Interchange level imports.

  • The option to bCombineStaticMeshes for USD Interchange asset imports has been hidden, as it could conflict with the new collapsing support.

  • Allow specifying custom render contexts for USD Interchange Schema Handlers intended for parsing material schemas.

  • Added support for spawning lights with Nits units on Interchange imports. Imports via USD Interchange will prefer the new Nits units when possible for direct correspondence with USD.

  • Added support for point and spot light source radius when importing via USD Interchange.

  • The USD Interchange import option for filtering imported geometry purposes has moved back to the USD Translator settings (it temporarily became a USD Pipeline option).

  • Interchange USD now supports prim collapsing, both via prim kinds and the dedicated collapsing schemas. The collapsing settings can be configured on the USD Translator settings (the three dots on the top right of the USD Interchange import options dialog).

  • Improved support for camera parameters when importing via USD Interchange, expanding support for clip planes, exposure method, exposure compensation value, and exposure FStop, ISO and shutter speed attributes.

  • Actors, components and assets imported via USD Interchange will only have their properties set to any value if the corresponding source USD attribute had an actually authored opinion. In other words, fallback USD values will no longer be converted into Unreal property values.

  • Refactored the USD Translator to use Schema Handlers: These are classes meant to each describe the translation of a particular USD schema. Users can implement, override, disable, enable and reorder schema handlers from project-level code and plugins, and e.g. implement translation of their custom USD schemas for USD Interchange.

  • Added support for directional light source angle when importing USD stages via USD Interchange.

  • The top-level actor spawned by USD Interchange level imports will no longer display the file extension of the imported layer as part of its display label.

• Added a GenericPayloadData class and an implementation of it on the USD Translator. This allows user code to describe brand new payload data, and to have schema handlers provide that data to user-provided Interchange factories.

• Imports and exports from/to USD may now cause point and spot light source radius values to be clamped to a minimum value, to ensure that the intensity values don't explode to infinity when converting to and from Nits to other light intensity units.

• Importing USD stages with light prims that contain "exposure" animations may now cause the intensity animation track to be baked frame by frame, as the intensity formula contains an exponential function that cannot be correctly interpolated with purely linear keyframes.

• Added a fallback for parsing light attributes from USD prims without the "inputs:" prefix, allowing for backwards compatibility with older scenes.

• Added support for exporting the Refraction channel when baking materials to USD. 1.0 will be used as the default for refraction when exporting translucent materials, to match the Unreal refraction value default.

• Fix missing assets and components on USD imports when the USD prim names differ only by letter casing (e.g. "/Cube" and "/CUBE" on the same stage).

• Added some feedback when the USD reimport fails due to the stage not having a valid prim at the same original prim path.

• Spawn all camera actors as movable when opening or importing USD stages.

• Fixed default refraction and displacement values on the USD preview surface reference materials to match the USD defaults of 1.5 and 0.0, respectively.

• Fixed how the USD Stage transform would not be baked into the OpenVDB texture when importing volume textures into SVT assets via USD imports.

• Interchange will now spawn all light actors with stationary mobility, following the behavior of the Place Actors window.

• Added support for exporting mesh component Overlay Materials to USD as referenced copies of the original mesh prims, but with different material assignments.

• Added support for Capsule_1 and Cylinder_1 primitive schemas when opening or importing USD Stages.

• The DomeLight_1 schema is now supported as the DomeLight schema when opening and importing USD Stages. When exporting to USD, SkyLights will be converted to the new DomeLight_1 schema.

• The USD Importer will now check that the provided reference materials configured on the USD project settings have the expected properties (e.g. the provided two-sided reference material must actually be two-sided).

• On the USD Stage Editor, it should now be possible to author references and payloads on prims that don't yet have a spec on the current USD edit target.

• Prevent the collapsing of prims with alternate draw modes when opening or importing USD stages.

• The Interchange inspector dialog now sorts nodes by name and type.

• Show an error toast when the Interchange import or reimport failed to produce any actor or asset.

• Clamp the subdivision level to a minimum and maximum on the Interchange USD import options dialog.

Bug Fix:

• Reset existing LODModels for reimport, so that Bone bindings and mappings are updated correctly. Also attempting to update SkeletalMeshEditor in case the re-import was triggered outside of the SkeletalMeshEditor.

• Fix a crash when importing some scenes via Interchange if some of the scene's assets fail to import and are canceled mid-import (such as textures failing to parse).

• glTF: Vulnerability fixes for glTF Reader.

• Fixed internal USD errors being uncaught and propagating to Unreal when triggering Async USD Interchange imports in some edge case scenarios.

• Fixed a crash when importing (via USD Interchange) stages with blend shape animation curves that happened to produce no valid curve data.

• Fix level sequence export to USD missing animated attributes of SpotLight components.

• Fixed how USD Interchange imports would produce duplicates of the same textures if the textures were used on different material inputs.

• Fix how the Interchange texture factory would delete existing texture assets when reimporting in some scenarios.

• Fixed how exporting levels to USD would not work with the traditional AssetExportTask Python snippet.

• Fix old assets still being referenced by the level and other assets after reimporting USD Stages in some scenarios.

• Fix texture assets imported via USD Interchange having names containing the source texture file extension.

• Fix static mesh actors imported for collision meshes via Interchange sometimes ending up with the render mesh assigned.

• Fix memory stomp on the stack in TiffImageWrapper. TIFFGetField expects a pointer to uint32 when using TIFFTAG_ROWSPERSTRIP but was passed a pointer to a uint16.

• Fixed Interchange showing the "There were issues with the import" toast when the recorded issues were due to previous imports.

• Fixed a crash when importing USD stages via Interchange and failing to find an existing material asset referenced by the stage via an Unreal Material prim.

• Fixed the handling of nested geometry purpose opinions when opening or importing USD Stages.

• Fix prim copy-paste behavior when selecting multiple prims at once on the USD Stage Editor.

• Prevent valid UTF8 characters from being unnecessarily sanitized away to underscores in some operations on the USD Stage Editor.

• Prevent loss of transform opinions in some edge cases when writing out attribute values to USD with a stage opened on the Stage Actor.

• Fix logic issue on the Interchange Inspector UI preventing the selection checkboxes from affecting the top-level nodes.

• Fix crashing when importing Geometry Cache assets from USD in some edge cases.

Scripting

New:

• Added a FindReferencesByTag function to the Gameplay Tags Toolset.

• Added a bOverwriteExisting option to CreateAsset, useful when automating/script object creation to not prompt.

• Added EBatchCreateFontAsset::CreateIfNoFontExists to help with automated importing not creating Foo_Font1, Foo_Font2 unncessarily.

• Exposed on option on UFontFileImportFactory to create a matching UFont for the UFontFace when programmatically/scripting importing a font.

• Added exposure to Level Editor Subsystem to Get and Set a level editor viewport camera's location, rotation and FOV Clamps FOV between 5 and 170 degrees, in line with the Editor UI spinner box UI.

• Require that SupportedClasses be filled out on UAssetActionUtility and UActorActionUtility Actions with no SupportedClasses filled out will now cause a data validation error.

• Added Optional property support to Python.

  • Python can now read and write Optional properties from UObjects and UStructs, where None is treated as unset.

    • Note: This does mean that you can't distinguish between an unset Optional and an Optional set to a null UObject, but the latter is an unusual use of Optional.

  • Python generated types can create Optional properties via a tuple of two values, where one is None and the other is the value type of the Optional (in either order),

    • E.g.:  ``` @unreal.uclass() class TestOptional(unreal.Object): prop = unreal.uproperty((str, None)) @unreal.ufunction(params=[(None, int)]) def func(self, opt): pass ```

• Exposed utils to import/export a string table from CSV to BP/Python.

• Scriptable Tools: Added MakeTransactional BP function to ScriptableInteractiveToolPropertySet so that tools can optionally enable transactions on a property set.

Bug Fix:

• Scriptable Tools:

  • Fixed ScriptableToolsFramework dependency on non-redistributable ToolWidgets module.

  • Refactored SDraggableBoxOverlay usage to isolate ToolWidgets as a dependency to ScriptableToolsEditorMode rather than ScriptableToolsFramework.

  • The coupling of ScriptableToolsFramework on ToolWidgets prevented runtimes from shipping the framework due to ToolWidgets non-redistributable status as part of the Source/Developer modules.

• Python-defined function return value fixes.

  • Fixed the order that packed return values are built, so they match the order that the types are defined (and match C++).

  • This was a bug previously fixed for the input arguments, but not the output arguments.

• Fixed crashes that could occur when reinstancing classes generated via Python.

• Fixed FPyWrapperSet::Intersection/IntersectionUpdate failing for builds where TSet was TCompactSet The updated implementation (iterating in reverse) works correctly for both TSparseSet and TCompactSet.

• Generate the TraceType/ObjectType ScriptName from the CollisionChannel DisplayName, if the CollisionChannel ScriptName is empty The old broken names are still available as deprecated aliases.

• Ensure the PythonScript commandlet enables source control prior to running the script Source control cannot be directly enabled in Python, so it's simpler to enable it from C++ before running the script.

UI

New:

• Tool Widgets

  • Deprecate SDraggableBoxOverlay.IsDraggable for Draggable to conform with established naming conventions. Deprecate SDraggableBoxOverlay.RestoreFromDragBoxPosition for SetDragBoxPosition to conform with established naming conventions.

  • Added resizing support to SDraggableBoxOverlay.

  • Make DragBoxPosition properties visible to details panel.

  • Added DragOverridesCenterAlignment to SDraggableBoxOverlay to allow dragging to override center alignment on either axis. This is useful for when we want a DraggableBoxOverlay to start centered but still allow users to customize its position.

• New experimental Semantic Search plugin: Changes content browser search to use a vector index-based search instead of the default keyword search.

• Teds Table Viewer Column: Support column metadata to disable sorting for a specific column.

• Added Gurmukhi to require full shaping.

• Hierarchy Editor: Multi-selection generalization for drag-drop and details panel.

  • Activated

  • Added option to turn off multi-selection via view model.

  • Disabled for Niagara (details customizations don't play nice).

  • Enabled for property bags (caveat: Only works well for same-type selections).

  • Drag initiates from tree view selection, not just the row under cursor.

  • All-or-nothing: If any element can't be dragged, entire drag refused with toast.

  • Hierarchy-aware: Parent+child selections skip child during drop (comes with parent).

  • Drop order always matches tree display order regardless of selection order.

  • Drag decorator shows "(+N)" for multi-element drags.

  • Drop validation checks all elements against target; all must pass.

  • SetObjects() for multi-object editing when multiple elements selected.

  • Name area shows "(+N)" badge; tooltip lists all selected elements via OnGenerateCustomDetailsPanelNameWidget.

  • New SupportsMultiEditInDetailsPanel() virtual to opt out.

  • F Dragged Element Entry: Element wrapper with bIsContainedInAnotherDraggedElement flag.

  • F Data Hierarchy Drag Drop Context: Wraps entry array with GetTopLevelEntries/GetPrimaryElement.

  • FHierarchyDragDropOp takes FDataHierarchyDragDropContext; CreateDragDropOp signature updated.

  • CreateDragDropOp overrides updated for new signature.

  • Custom drag decorators render all elements vertically for multi-drag.

  • Multi-edit disabled via SupportsMultiEditInDetailsPanel.

  • FInstancedStructDataWithHeaderDetails uses EnumerateConstRawData instead of GetValueData.

  • Fixes missing category headers (e.g. "Numeric") during multi-object editing.

• Added a Crash Diagnostics panel to the Editor Diagnostics window to view recent editor crashes.

• Add button to enable/disable editor shortcuts when PIE is active.

• Added Dynamic Invalidation to the Material Editor Graph.

• Added Data Hierarchy Editor support to FInstancedPropertyBag:

  • PropertyBagSchema class can now direct the property bag details to an optional HierarchyRoot object.

  • PropertyBagSchema class also contains information about hierarchy types.

    • This can be used to subclass and add properties.

  • Moved some util functions around hash calculation into public

  • Replaced some UEdGraphSchema with UPropertyBagSchema.

  • Added more encapsulation so that FPropertyBagInstanceDataDetails is more standalone and can be subclassed.

  • Removed some of the construct params in favor of FPropertyBagInstanceDataDetails looking relevant data up via property handle.

  • Added InstanceMetaData support to allow forwarding metadata to an inner FInstancedPropertyBag.

• S Subobject Editor::FindSlateNodeForHandle: find slate node for FSubobjectData that doesn't have a WeakObjectPtr but does have a corresponding teds row.

• Project Launcher fixes for recent changes in Cooker behavior:

  • Zen Streaming content scheme is only used for new profiles when bUseZenStore and AllowRemoteNetworkService are set.

  • Add profile validation error when trying to use Zen Streaming to a remote device when AllowRemoteNetworkService is false.

  • Platforms menu Quick Launch disables unversioned cook when using LegacyIterative.

• Added Dynamic Invalidation to the Place Actor Panel.

• Added Dynamic Invalidation to the Content Browser.

• Added Dynamic Invalidation to the Scene Outliner.

• Added support for drag-and-dropping a texture onto an existing texture sample node to replace the texture.

Bug Fix:

• UMG/Slate

  • Fixed SListView ScrollIntoView alignment math (local-space deltas and CenterAligned culled-target offset) so centered and partially clipped items scroll correctly at non-default DPI.

  • Fixed proximate intra-entry navigation to reject focus targets outside the list bounds when bEnableProximateEntryNavigation is enabled.

• Fixed crash in PropertyPathHelpers::SetPropertyValueFromString when propagating properties to widget archetype instances.

• S Draggable Box: Fix for single right-click entering drag mode.

• Fixed selection outline of Nanite-enabled mesh components when selecting individual components below an actor. Previously, deselected components on the same actor would not render with the muted outline color.

• Fixed the editor selection outline of Nanite-enabled Skeletal Mesh and Instanced Skinned Mesh components.

• Fixed overlay colors not working with non-Nanite Instanced Static Meshes.

• Fixed nullptr dereference when generating tooltip in widget reflector for native widget class types.

• Tool Widgets: Fixed SDraggableBoxOverlay accumulating Padding when invoking SetBoxAlignmentOffset with center alignment.

• Fixed crash when dismissing notifications after hot-reload.

• Fixed right click crash on tagged asset browser sections.

• Fixed incorrect transform handling of static meshes in the viewport.

• Optimize select actors in statistics tab.

• Fixed edit change conditions not correctly gathering the edited UObject if it's an instanced struct that was added to the UI, as a complex parent was found on the way up that was not the owning object node.

• Fixed missing objects in property change event for edit condition toggling.

• Fix an issue where Status Bar tool tips appeared in another screen (or overlapped the status bar if there was no monitor to the right).

• Added IsAssetVisible check for tagged asset browser extension functionality.

UX

New:

• Added new input settings tab containing keyboard shortcuts and future shortcuts.

  • Added sidebar to settings editor that shows left panel when more than one item (docked) and hides when it contains a single item.

  • Import/export (All) will only handle shortcuts instead of all editor settings now.

  • Updated autocompletion and suggestions to use new container.

• Improved Settings Editor UI to match the rest of the editor (tree view, splitter, category, style).

  • Improved search to only apply to the selected section instead of showing all results.

  • Improved Filters and suggestions to be dynamic and (dis)allow specific sections (they only appear in the proper context).

  • Added keybind action button to search for specific keys pressed.

  • Allow partial search match from begin or end.

  • Added icons for keybind and cvar filters.

• Added advanced preview scene options to customize floor, floor rotation, floor scale and floor material.

  • Added advanced preview scene option to clone a profile from existing ones.

  • Added advanced preview scene keyboard shortcuts to navigate to next/previous profile (SHIFT+ALT+Up/Down).

  • Reworked the preview scene settings tab UI.

  • Property AssetPicker can now be customized with additional metadata to set ViewType, ThumbnailSize, ThumbnailScale, SettingsName.

  • Deprecated "show grid" property since it's not relevant to all context.

  • Fixed preview scene not loaded properly on editor startup.

• Property Editor: Add an option to add a color bar on every row in the category.

• Persist import interpolation mode for reimporting CSV as curve table.

• Interactive Tools Framework: Modified UInteractiveToolPropertySet::SaveRestoreProperties to only instantiate a property cache entry when saving. This permits successive calls to RestoreProperties to behave as expected, particularly in the case where a tool inherits from a base tool class, but wants to modify the defaults of an inherited property set. In that scenario, both the base class and derived class would issue RestoreProperties on the inherited property set.

  • Prior to this change, the first call to RestoreProperties would instantiate the property cache and detect that the property cache was just created to avoid the restore. The second call to RestoreProperties would incorrectly see the just created property cache as evidence that there is saved data to restore and copy the default CDO data to the tool.

  • By only instantiating the property cache on save operations, the behavior is more consistent and avoids tools having to create awkward workarounds using separate property cache IDs to workaround the issue.

• Fixed combo box widget tooltips appear on dropdown list items across the editor making it hard to navigate across options.

  • Added a way to extend force repel zone on any widget with a slate attribute.

• Added scale option in config for warning/error messages in texture editor viewports.

• SSegmentedProgressBar is now available for displaying the progress of a multi-state workflow.

• Replaced delete content browser popups by dialogs to attract user attention (folders, favorites, collections).

  • Improved delete dialog widget to include pending deletion folders.

  • If the folder is not empty and contains assets, a first dialog will be shown to avoid loading all assets recursively on a mis-click otherwise only the main delete dialog widget will be used.

• Re-enabled delayed change notification on SceneOutliner search.

• Added asset class icon with color to the save all dialog content table row.

• Updated content browser suggestion filtering so only paths starting with the currently typed text are shown.

• Open editor, project, input settings in "All settings" by default instead of "Appearances" and "General" since search is now localized.

  • Auto focus search box when opening settings.

• Added drag and drop support from content browser to material editor viewport to change preview mesh.

  • Dropped preview mesh will become default preview mesh when reopening asset editor.

• Added Material Instance to custom filter in content browser to search for these asset type.

• Add recursive expansion/collapse on TreeViews when navigating with the arrow keys to match the shift-click expansion arrow behavior.

• PCG Property Bag: Hierarchy Editor Support added.

• The editor layout now properly restore the position and scale of the level editor window position and the other windows managed by the tab manager.

• If CTRL is pressed and folder are dragged then copy/move folders is performed on drop.

  • If CTRL is not pressed and folders are dragged then add/reordering favorites is performed on drop.

  • If favorites folders are dragged then reordering is performed on drop.

  • If file assets are dragged then copy/move items is performed on drop.

• Fixed ToolTip Override that was not working for FPropertyHandleBase::CreatePropertyNameWidget.

• Show Favorites/Modified sections in details panel filter bar, use details settings and check "Show Helper Sections"

  • Add/Remove category items from favorites using context menu on a category.

  • Expand/Collapse details panel root categories using shortcuts : CTRL+SHIFT+X and CTRL+SHIFT+C, menu entries and commands actions are now using the same code path.

  • Fixed SHIFT+Click on expansion arrow do not recursively expand advanced category.

  • Grouping properties based on their original category in favorites and removing Advanced.

• Enabled search in data table row editor.

• Allow reordering of favorites list (above or after).

  • Disallow move or copy operations of folders in the favorite list.

  • Added edit favorite dialog to set an alias and shortcut to a favorite item (through context menu).

• Content Browser - Column View : Added description of how many columns are displayed and from what asset type they are from. Without that information, it's hard for a user to understand there are some missing columns simply because they're not part of the columns of the asset type for which there's the most assets on display.

• Added context menu entry in editor preference and project settings to copy associated CVar to the clipboard if any.

  • Added row extension button to quickly spot properties with a CVar and copy them to clipboard.

• Improved "Keyboard Shortcuts" editable input UI to follow unreal theming.

• Fixed ContentBrowserModule's "AssetClassesRequiringDynamicTags" feature. It now stores classes as FTopLevelAssetPath in order to properly detect them. Also, now, child classes of an asset class requiring dynamic tags are also considered requiring dynamic tags.

• Added an option to sort the content browser filters in alphabetical order or insertion order.

  • Refactored loading filter code to restore filter in the correct order instead of the random type registration order.

  • Reordered all context menus in the content browser to be alphabetically sorted (Other filters, Custom filters, Common filters).

• Added Open Screenshot Folder button to High Resolution Screenshot tool.

• Added browse to asset when right clicking the tab of an editor asset tab, action is only enabled for assets (non transient).

  • Added browse to level when right clicking the tab of an editor level tab, action is only enabled for saved level.

• Use the class display name when showing the asset type in the generic asset viewer (as we do in the Blueprint editor).

  • The tooltip now for the "go to source" hyperlink shows the native class name for both the Blueprint editor and asset viewer.

Bug Fix:

• Fixed sidebar widget stays in an intermediate state when clicking multiple times on the sidebar button.

• Asset thumbnail: Fixed color that was not updated to match the asset type color in some cases.

• Fixed Blueprint Editor Drag and Drop of asset in tree hierarchy does not match user intent.

• Fix an editor crash that could occur for reset to default on class reference values in the details view.

• Fixed non-displayable references list is not interactable when deleting pending assets in dialog.

• Fixed set and map property editors that would not show "Multiple Values" when editing multiple objects with a different number of items (they both behave like the array property editor now).

• Fixed asset search box suggestion width should match search box width instead of changing based on in view content.

  • Fixed content browser search suggestions should appear above to avoid obfuscating filtered results.

• Content Browser: Fixed an issue where the previous opened path would not always be restored properly when rebooting the editor.

• Add missing support for instanced struct value edit propagation and some fixes for its reset to default UX.

• Fix for stomping an annotation that has already been set during edit change propagation.

  • (Example) This was (incorrectly) marking child BP assets as needing to be saved if they happened to be open for edit alongside their parent in the BP editor, in cases where they would (correctly) not be dirtied if not also open for edit.

• Fixed the AI assistant tab label centering in the Panel Drawer.

Foundation

New:

• Optimized FSplineMeshSceneProxyDesc::CalculateShaderParams to skip calculating the MeshDeformScaleMinMax if the mesh isn't nanite enabled. MeshDeformScaleMinMax is only used for nanite LOD calculations and computing it is very expensive.

Bug Fix:

• Based on, fixed two issues in primitive drawing utilities:

  • DrawFlatArrow now correctly applies the thickness parameter, which was previously unused.

  • F Batched Elements::AddReserveLines no longer reserves twice the required number of line entries, reducing unnecessary memory allocation.

• Fix FCompression initialization could occur on first use on a thread, causing a crash.

• Quote path of PerfreportTool.dll when calling it from AutomatedPerfTestNode.

Build

New:

• Update Intel OneAPI supported version to 2026.0.0.

• Add UE_PLATFORM_* definitions to mirror existing PLATFORM_* definitions.

• SN-DBS now uses per-platform tool template directories to avoid rare cases of ambiguity when compiling for several platforms at once.

  • Requires SN-DBS 2.6.10.1020 or later to utilize the new code path. Support for older versions of SN-DBS remains, but UBT will emit an error if it encounters a situation that requires the upgrade.

• Added -SkipEncryption support for IoStore containers.

• Remove 2GB limitation when generating psym files by never storing the output as a string.

• UhtSpecifierValueType.Legacy is now obsolete. UhtSpecifierValueType.None should be used in its place.

• Added packaging option to allow specifying alphabetical-cluster-sort and alphabetical fallback ordering for a specific prefix match of container names.

• Added support for patterns such as "FString()" for default values in UFUNCTIONs.

• Build Graph: Added option ErrorIfNotFound to RetrieveArtifactTask to control if an error is thrown when an artifact cannot be found.

Bug Fix:

• Add support for UStructs in namespaces for TInstancedStruct properties.

• Set DefaultBuildSettings for the BlankProgram template. This prevents compilation errors when the template is used outside the engine folder.

• Add support for UStructs in namespaces within RigUnit.

• Fixing an issue where types wrapped in WITH_EDITORONLY_DATA would not have that definition reflected in the generated code.

• SNDBS: Prevent exception when there is no explicit_input_files key.

• `class IFoo {... }; UCLASS() class UFoo : UObject {... };` no longer results in an error claiming that IFoo is missing GENERATED_BODY().

• Fixing issue where delegates were not properly bound by #if/#endif pairs in their definitions. Added "Editor" as a distinct defined scope separate from EditorOnly.

Compile Time Improvements

New:

• Reduced linking time on clang with LTO by disabling debug info upgrading, sice we build everything with the same toolchain.

Core

New:

• DDC

  • Added record/value to cache put responses to give callers a copy of what ended up stored in the cache.

  • Added ApplySkipPolicy to apply ECachePolicy::Skip to values and records.

  • Added a constructor for FCacheRecord from FCacheKey.

  • Added TryLexFromString for FCacheKey and FCacheBucket.

  • Added support for natively-async cache stores to skip creation of an async wrapper.

  • Added cache store tests.

  • Added custom cache graph support with, e.g., -DDC=(EnginePak,Cloud), or in the same format with the DDC.Graph CVar. Any configuration that is valid in a graph is supported, such as -DDC=(ZenLocal,Cloud(ReadOnly=true)) to create a graph with ZenLocal and a read-only Cloud.

  • Added BuildLegacyCacheKey to support migration from the legacy API.

  • Removed unused short key and legacy mode functionality.

  • Updated graph creation to use the new config API.

  • Require that RawHash matches when present in GetChunks(). It was a hint and now it is a requirement to avoid callers receiving different data than they anticipate.

  • Added ECachePolicy::NonDeterministic to flag known-non-deterministic data to avoid noise in -DDC-Verify mode.

  • Serialize put requests into replays and replay them as gets.

  • Improved DDC graph selection. Consider every -DDC=... command line argument as a candidate. Removed broken -DDC=None functionality. Fixed DDC.Graph CVar overriding the installed default by making it empty by default. Added -DDC-NoDefaultGraph command line argument to remove the default graph from consideration.

  • Added a linear-probing hash table for internal use by DDC and DerivedDataTool.

  • Added a concurrent chunked sparse array for internal use by DDC and DerivedDataTool.

  • Removed obsolete DDC WaitForQuiescence from AppPreExit.

• Compact Sets: Resolved remaining issues to allow compact sets to be enabled safely:

  • Re-added key storage to ensure full compatibility with GC and object relocation.

  • Fixed natvis and GDB printers for sets and compact sets.

  • Removed unused feature auto relax map.

  • Reworked compact set lookup algorithm to account for some specific edge cases.

  • Improved run-time detection of broken lookup, usually due to external memory changes.

  • Added BuildConfiguration option bUseSparseSetStrictMode that, when enabled, will cause spare sets to be more strict in their usage so compile issues can be fixed to allow switching over to compact sets.

  • Added BuildConfiguration option bUseCompactSetAsDefault that, when enabled, will swap the implementation of TSet and TMap to use compact sets instead of sparse sets. TCompact[Map|Set] and TSparse[Map|Set] still exist for explitic usages, but explicit forms cannot be used as UPROPERTY's.

  • Perf: Enabling compact sets in Fortnite saw 40-90MB of memory savings, depending on platform, as well as overall improved performance in most CPU threads.

• Add TSubScriptStructOf. Similar to TSubClassOf but for UScriptStruct. Add an editor picker that works with NoClear and the metadata.

  • Meta Struct: The struct path of the base struct displayed in the picker.

  • Show Tree View: The picker uses a tree view or a list view to display the available struct.

  • Show Display Names: Uses the DisplayName of the selectable struct.

  • Hide View Options: Hides the options menu in the picker.

• Struct Utils: FInstancedPropertyBag serializes with the default values. With tagged serialization, the full instance will be skipped if the descriptions and the values are the same. If the descriptions are the same, only the values that are modified will be serialized. If the descriptions changed, then the default is not used. When using FInstancedPropertyBag in a BP, it might appear that it works without this changelist. This is due to the reinitialization process during compilation. Without this change list, it might not work depending on the loading order.

• Added "UObject Count" trace counter.

• Introduce indirection for AssetRegistry cache files, so we don't need to overwrite them.

• Introduced UE_JSONOBJECT_LEGACY_STRING_KEYS which defaults to 0, set to 1 to revert FJsonObject to its FString-based interface.

• Replaced the hash for FNameEntryId to avoid extremely poor worst-case distribution.

• Added asset chunks deduplication option in UnrealPak for IoStore containers, accessible via [/Script/UnrealEd.ProjectPackagingSettings] bDeduplicateChunks=true.

• Added C++ Concept for pointer convertibility.

• Added support for non-power-of-two FName pool shard counts, to allow alleviating hash table load without needing to double the capacity.

• `TVariantPtr` no longer requires non-UObject type to be `TSharedFromThis`, accepts `TSharedPtr`.

• Added the concept of auto-loading non-plugin modules based on.ini settings (see Auto Load Modules By Phase: And [AutoLoadModulesByPhase_Editor] in BaseEngine.ini).

  • Making use of it to load TargetPlatformManagerModule earlier to kick off the async UBT process.

• Prevent LexToString(bool) from hijacking types that implicitly cast to bool. This makes missing or unresolvable LexToString overloads fail at compile time instead of being hidden by a bool conversion.

• Added UE::CInsertable as a proper concept and UE::CInsertableInto that reverses the parameters.

• Added FText::AsMemory overload accepting a specific EMemoryUnit.

• Fix json library to use actual object class instead of static class from templated class type.

• GC: Add the option to GC based on pending actors to unload (in addition to existing mechanism that uses number of levels) for finer control (disabled by default). Number of levels can be inaccurate given the discrepancies between level counts and memory impact. across main grid / data layers Add the option to GC based on pending actors to unload (in addition to existing mechanism that uses number of levels) for finer control (disabled by default). Controlled via `s.ContinuouslyIncrementalGCWhileActorsPendingPurge`/ `s.LevelStreamingLowMemoryActorsPendingPurgeCount` and `wp.Runtime.LevelStreamingContinuouslyIncrementalGCWhileActorsPendingPurgeForWP` (for partitioned worlds).

• Added the frame counter (when present) to structured log output.

• Oodle updated to 2.9.16.

• Added natvis visualizers for Compact Binary.

• Added MoveAssignScriptStruct to UScriptStruct for move-semantic support in type-erased struct operations. Introduced the WithMoveAssign trait on TStructOpsTypeTraitsBase2 (following the pattern of WithCopy), the STRUCT_MoveAssignNative flag, the FCapabilities::HasMoveAssign capability, a MoveAssign fake-vtable entry, and ICppStructOps::HasMoveAssign() / MoveAssign(). STRUCT_MoveAssignNative dispatches to C++ operator=(T&&); STRUCT_IsPlainOldData uses memcpy; the fallback calls CopyScriptStruct for zero regression on non-opted types.

• Parking Lot: Use low-level virtual memory API for allocations to allow our allocators to depend on ParkingLot.

• Rename some private stats types to avoid collision with platform SDKs.

• Deprecate and remove the FField virtual functions Bind(), PostLoad() and BeginDestroy() that are implemented but never called.

• Added && TShared/Weak... constructors and StaticCastShared/Weak... helpers. Removed WeakPtr from TSharedFromThis.

• Changed MallocBinned3 max small bin config to 14kb by default as it offers better performance\memory in our testing.

• Added filtering by key to the derived data cache key filter used for simulated misses, verification, and replay.

• Added IsLockedByCurrentThread() to the recursive mutex types.

• Implemented an easy-to-use mechanism for deprecating existing cvars.

• Asset registry cache will now memory-map its tag data storage, reducing RAM footprint by GBs in large projects.

• Made TSharedString transactionally safe by using TTransactionalAtomicRefCount.

• Converted UE_LOG to use log records internally. This adds file, line, and context to every UE_LOG even though they are inherently unstructured.

• Simplify serialization of ClassFlags in UClass::Serialize by updating and always using CLASS_ShouldNeverBeLoaded.

• Reduced the stack cost of a failed ensure from ~32 KiB to ~2 KiB.

• Added packaging of Derived Data Build Workers and updated DerivedDataTool to work with them.

• Made UTF8TEXTVIEW constexpr.

• Added -CookPackageDir= to the cooker to allow cooking a directory, and when combined with -cooksinglepackagenorefs, then only that directory will be cooked.

• Added a DerivedDataBuildController to support compiling shaders through the Derived Data Build API.

• Improved to the Derived Data Build Worker startup time. Fixed directory deletion in the local executor for the Derived Data Build Worker.

• Runtime: Add: WebRTC initialization on Android.

• Optimized variable-length integer encoding in VarInt.h.

• Allow an IInstallBundleSource implementation to override the default PAK mount priority via its FInstallBundleSourceUpdateContentResultInfo.

• Added OnHDRScreenshotCaptured delegate to UGameViewportClient, fired when an HDR screenshot is captured. OnScreenshotCaptured does not fire when HDR is enabled. A separate delegate is needed to allow returning the HDR bitmap as TArray<FLinearColor> rather than TArray<FColor>.

• Removed unnecessary dependencies from LauncherServices, RenderCore, ShaderCompilerCommon, and TargetPlatform Reduces the size of programs like ShaderCompileWorker that do not otherwise depend on some of the removed dependencies.

• Added TargetRules.bEnableConfigSystem to allow disabling loading config.

• Enable range-based for loop support for `TFilterCollection`.

• Commandlets will now print peak used memory at the end of their execution.

• Added option in UnrealPak to keep unchanged assets at the same file offsets in IoStore containers as they were in the previous build, accessible via [/Script/UnrealEd.ProjectPackagingSettings] bUsePatchInPlaceLayout=true.

• No longer performs a normal config save if the PreSaveConfigFileDelegate returns that it saved the file. This can reduce some slow unnecessary disk operations on some platforms. Can revert to original behavior by either setting ini.SkipSaveIfPreSaveSucceeded to 0, or by not incrementing SavedCount from your delegate implementation.

• Add cvar, core.EnsureBreakEnabled (default:True), to disable debugger breaking when ensure statements are hit to allow skipping unrelated ensures while debugging longer processes.

• Added a DerivedDataTool Copy command to copy data between caches.

• TLruCache: Add SetMaxNumElements / Declare default move constructor/assignment and define proper copy/assignment as they are currently broken (with unittest) [PCG] Cache: optimize cache grow and use SetMaxNumElements instead of the previous full copy that was happening.

• Streamable Manager:

  • Added a mechanism to just-in-time trickle async load requests on a streamable handle.

    • Added a mechanism to batch/trickle async load requests on a streamable handle.

      • Opt-in (enabled via UE_ENABLE_STREAMABLE_JIT_ASYNC_LOADING=1) and by setting bUseJustInTimeAsyncLoader=true or if batching is enabled globally (s.StreamableEnableJITAsyncLoadingGlobally).

    • The initial batch size is set as per s.StreamableJITAsyncLoadingInitialBatchingFactor which is a factor of the total number of requests queued for a streamable handle (default is 0.25).

    • This can be used to cancel or queue subsequent async load requests at updated priorities (see FStreamableHandle::SetPriority) which would get picked up when subsequent requests are queued.

    • Opt-in by setting bUseJustInTimeAsyncLoader=true or if batching is enabled globally (s.StreamableEnableJITAsyncLoadingGlobally).

• Optimized FMath::RoundUpToPowerOfTwo[64] for Clang.

• Used MPSC queue instead of MPMC queue for log output.

• Added && to Value and operator* in TOptional.

• Refactored UObject::LoadConfig into some Context objets to break up the wall of code and also be able to more easily add functionality (like passing a preloaded FConfigFile to LoadConfig).

• Added TAutoConsoleVariableDeprecated_NoReplace CVar type that is used to deprecate a cvar without replacing it with another one. The value can still be queried, but it will ensure (or warn or assert depending on setting). Similarly, FAutoConsoleCommandDeprecated_NoReplace was added for deprecating a command without pointing at another.

• Added support for an optional.ini file that is applied after engine/project plugins and before GFPs and Hotfixes. This allows a project to override plugin settings if needed (likely to be rare, but there is a use case for it). It is called PluginOverride.ini (ie PluginOverrideEngine.ini) and is stored in Project/Config. There is no per-platform version.

• Added bool return type to FConfigCacheIni::Flush to know if the information was actually written to disk.

• Added parameters to TGuardConsoleVariable to be able to specify priority when setting cvars from testcode.

• Added FrameNum and UTC time to stat unit so we have a way to match up video captures with logs, etc. Requires setting "stats.UnitTimestamp" cvar to enable.

• Use UTF-8 for structured logging format strings.

• Added the UE_LOGF family of macros for unstructured logging with UTF-8 format strings.

• Added FPlatformString::FormatV and TCString::FormatV to provide GetVarArgs with a usable return value.

• Add EAllowShrinking arg to TIndexedContainerIterator::RemoveCurrent and TIndexedContainerIterator::RemoveCurrentSwap.

• Added concept UE::CContiguousRangeOrRef.

• Moved GetDataHelper to UnrealTemplate.h.

• Assert on re-entrant calls in ParkingLot to catch invalid usage by callers.

• Added WaitFor and WaitUntil to FConditionVariable.

• Added console command to reload a package in the editor, including in -game obj reloadpkg package=/Game/Foo.

• Added the OptStreamGotTo optional param to most of the FParse::Value() functions (it was only on string versions before). Didn't add to FText version because it uses a different parsing code that doesn't return the end of the value.

• Added trait TIsCharEncodingCompatibleWithUTF8CHAR.

• Add error detection for SQLiteSupport.

• Moved log category macros to LogCategory.h.

• Fixed WarnFilterScope for structured logging and added CHECK_LOG_SCOPE for common cases.

• Cleaned up the unused FConfigFileHierarchy::DynamicKey code.

• Allow plugins to have PluginName.ini along with Base/DefaultPluginName.ini (but deprecated).

  • Also deprecated BasePluginName.ini so we can eventually look for fewer ini files during plugin mounting.

  • Show a message with GFP old style names as well.

• Removed unnecessary confighierarchy entries, and plugin config branches that have no static layers.

  • Removed the "config xxxx" console commands in SHIPPING.

• For GameFeaturePlugins, renamed Conole Variables: And [ConsoleVariables_HighPriority] to [PluginCVars_LowPriority] and [PluginCVars_HighPriority]

  • Added initial support for them in Preview, although it only works if in Engine.ini files, a future change will work to address this.

  • GFP Hotfixes still use Console Variables: Because they set at Hotfix priority, not Plugin.

Bug Fix:

• DDC

  • Allow records with no values in the Memory cache store. DDC: Report an error when the memory cache store exceeds its size limit. DDC: Verify that content exists in the FileSystem cache for differing values even if they are expected to be non-deterministic.

  • Fixed Zen client support for out-of-bounds chunk reads.

  • Fixed out-of-bounds chunk reads in the memory cache store.

  • Validate RawHash in compressed buffer headers to mitigate invalid data being returned by Zen.

  • Fixed a dangling string view in TryFindCacheGraphConfig.

  • Fixed a file system cache store race with initialization of FRandomStream relative to starting the maintenance thread.

  • Fixed a crash in FTimeAveragedStat and added tests.

  • Fixed use of ',' as a delimiter in unquoted arguments for simulated miss types and keys in DDC.

  • Fixed a DDC crash when recovering from a failure to create a non-default graph containing a pak store.

  • Fixed Cloud DDC reauthentication during shutdown by ensuring that DesktopPlatform unloads after DDC.

• Add a CVar named "Serialization.EnforceLinkerObjectBounds" (default true) to bounds check object data reads from.uasset in editor - this makes loading data after changing a variable type safer.

• F Instanced Struct Container: Fix missing default initialization of items prior to serialization on load causing invalid values if delta serialized.

• In FMonitoredProcess::TickInternal(), set bIsRunning = false _before_ calling OnCompleted(), so a Completed delegate can call GetFullOutputWithoutDelegate() without asserting. (Same change to OnCanceled())

• Fixed a dangling pointer in FConfigContext when using TemporaryBranch.

• Fix FName::CompareSensitive not always comparing case-sensitively.

• Allow newly created packages with a file on disk to be reloaded.

• Updated "stat fps" frame time indicator to use the same smoothing factor as "stat unit".

• Windows Platform File: Fix IterateDirectory to honor the contract to return false if the input directory does not exist. Keep the behavior that it returns true for directories that exist but are hidden or otherwise uniterateable.

• Updated FObjectPropertyBase::ParseObjectPropertyValue and FSoftObjectPath::ImportTextItem to handle parsing object paths with spaces in them.

• GameFeaturePlugins can now work from locations listed in AdditionalPluginDirectories (in a.uproject).

• Do not reset external package when renaming actor changing outer in PIE packages, fixing the asymmetry.

• Core/HAL: Fix: FSharedEventRef not respecting EEventMode passed in to the constructor.

• DiagnosticCheckNaN functions in various math library types no longer change the object being tested to a non-0 default value. This will increase the number of log messages but the old behavior involves mutation in a const member function and was a potential data race.

• Adjust CheckObjectValidBasedOnItsFlags to be consistent with other validity check such as TWeakObjectPtr::Get.

• Ignored SetColor verbosity in FOutputDeviceDebug.

• Fix for CrashReportClient reading project settings when bAllowNonUFSIniWhenCooked is set.

• Log an error if the class import doesn't have an outer (i.e reported as a package) when calling GetExportClassPackage.

• Fix multiple bugs where object flags and properties were not correctly copied over during reinstancing.

• Fixed a potential FPropertyTag issue when saving a static array with a property guid.

• Disabled the logging backlog at the end of PreInit for program targets to avoid unbounded backlog growth for programs that do not call GEngineLoop.Init().

• Fixed restarting workers with the incorrect number of task workers if the platform has a thread config. Changed the code to reinitialize with the existing number of workers.

• Fix for CriticallyDampedSmoothing when using target velocity.

• Correctly set ETaskTag::GameThread for the lifetime of the LowLevelTests test runner.

• Fixed initialization of the static thread ID in FTaskTagScope.

• Added a compiler flag to allow the work-stealing task queue to explicitly yield the thread if it fails to steal a job after a certain number of iterations (to avoid a deadlock).

• Fix for a rare memory stomp inside ServerMoveClientError. It is possible for the ServerPredictionData to be nullified part way through this logic (through a delegate fired in MoveComponent), which would mean the ServerData pointer is pointing to stale data. Reacquiring the ServerPredictionData guarantees the data is valid. Fixed a rare memory stomp inside ServerMoveClientError if MoveComponent causes a call to Unpossess.

• Adding FMA intrinsics when compiling with MinimumCpuArchitectureX64.AVX2 on Clang.

  • This fixes a compile error in the Eigen library when compiling AVX2 on Dedicated Servers using Clang.

  • This is because when compiling using the VCToolChain using Clang, we still define _MSC_VER so the Eigen library assumes FMA is included because MSVC always includes those intrinsics when using /arch:Avx2.

  • This change brings our Clang configuration in line with MSVC when using AVX2.

  • Note that this does not change the ffp-contract behaviour, so will not allow the compiler to optimise multiply add operations automatically.

  • Added FMA intrinsics when compiling with MinimumCpuArchitectureX64.AVX2 on Clang.

• No longer reconstructs a subobject after instancing its missing outer if it already constructed the subobject from the source archetype (optimization).

• Fix TPagedArray not forwarding allocator to internal Pages array.

• Remove the IniKeyDenylist and IniSectionDenylist from all layers of the BinaryConfig, instead of just the final InMemoryFile.

• Fixed TFunctionWithContext to support function pointers.

• Added some thread safety to FConfigCacheIni::ReadString (which the others like GetInt go through), SafeReload, and AddDynamicLayersToHierarchy.

• Apply FObjectInitializer instancing exclusions only to the object being constructed/initialized.

• Fixed TFunctionWithContext to support assignment from a const lambda.

• Disable editor-only data for non-editor platforms in FoundationTests.

• Fix duplicate warnings when LoadObject fails and improve the messages.

• Fixed access violation in libcurl 8.12.1 when under heavy load from during cook commandlet. The curl team has already fixed the issue in 8.16 and later.

• Fixed FHashTable buffer overrun on shrinking.

• No longer loads plugin ini files from subdirs (like Tags).

• T Compact Set: Ensure that elements are rehashed after being serialized during reference replacement.

• Fixed a HybridPackageStore init issue when no zen snapshot exists.

  • Fixed some issues with getting PackageStore info when we don't have a package name (in ImportPackagesRecursiveInner sets bHasImportedPackageNames to false).

• Updated UE_LOG_CONTEXT to be safe for use in transactions.

• Task Graph: Fix TGraphTask execute scopes not being emitted to Insights when using lightweight stats. Fix TGraphTask execute scopes not being emitted to Insights when using lightweight stats.

• Removing an unneeded CheckSlow in TCircularBuffer(uint32 Capacity) constructor that was checking for a capacity of 0. FMath::RoundUpToPowerOfTwo returns 1 for both a value of 0 and 1 so the buffer is established with a valid capacity regardless of what's passed in so the check isn't needed.

• When writing out the config file in FConfigFile::UpdateSections, don't write out the file if it matches the current file. This will make it so files like DefaultEngine.ini don't get marked as "changed" by some source control.

  • Slightly changed the COnfigModificationTracker class to be able to use bTrackLoadedFiles more often with worrying about tripping the code to not load a file that was already loaded (reducing side effects of using bTrackLoadedFiles).

  • Now added context in the Console Variables:/[COnsoleVariables_HighPriority] deprecation ensures.

• Fixed missing assignment of OutObjectId in MakeReferenceIds in FObjectHandle.

• Fixed console command arg parsing to support ""

• Added loop break in EarlyPlayFrameTick if engine exit has been requested to fix related hangs.

• F Tick Function Task::DoTask and FBatchTickFunctionTask::DoTask functions' TickContext parameter have the proper TickGroup set (instead of always being TG_PrePhysics).

• Fixed conversion from TArray in FArrayProperty.

• Fix for decltype on angle delta functions.

• Fix bug with FUnitConversion converting values that did not need converting. Resulted in values that were slightly off due to conversion precision limits.

• Fixed an incorrect optimization in FString::MatchesWIldcard and related funcs. It would flag matches incorrectly in certain rare cases.

Deprecated:

• Deprecated functionality in the UE4 API DDC that is no longer supported.

• Deprecated FCoreDelegates::OnPostEngineInit in favor of FCoreDelegates::GetOnPostEngineInit() to fix missing registrations that occur during static initialization.

• Deprecated PLATFORM_ENABLE_POPCNT_INTRINSIC and the associated FPlatformMisc::HasNonoptionalCPUFeatures() and FPlatformMisc::NeedsNonoptionalCPUFeaturesCheck().

• The UObject::Rename flag REN_ForceNoResetLoaders has been deprecated as UObject::Rename will no longer call ResetLoaders or flush loading during renaming as this was the cause of unnecessary loading stalls, and could introduce hard to diagnose bugs due to the sync load in the middle of a possible temporarily, intentionally incorrect UObject state such as during Blueprint reinstancing.

  • Rename will still attempt to maintain a package's Linker export mapping as renames occur unless the flag REN_AllowPackageLinkerMismatch is provided. As a result without specifying REN_AllowPackageLinkerMismatch, Rename will detach the linker from a loaded object whenever the object is moved to a new package.

  • Similarly, renaming a loaded object without specifying REN_AllowPackageLinkerMismatch will detach the export object from the linker that loaded it allowing future package requests for the same package to load a new object instance using the original object name if no object redirector was created during renaming (i.e. REN_DontCreateRedirectors).

  • If an object is being renamed and future package reloads should not create a new instance of original object name, InvalidateExport() should be called on the object before renaming. In cases where one wants to temporarily rename a loaded object and then rename it back to its original name, (REN_AllowPackageLinkerMismatch | REN_DontCreateRedirectors) should be provided as your rename flags to ensure the export is not detached.

• Deprecated PLATFORM_TCHAR_IS_4_BYTES.

Dev Tools

New:

• Unreal Build Tool

  • Support for APX for x64 architecture.

  • Implement.pvsconfig support for PVSToolchain.

• Added TraceQuery, a CLI tool for querying.utrace files as JSONL.

  • TraceQuery is a lightweight standalone UBT program that reads Unreal Engine.utrace binary trace files and outputs structured JSONL to stdout, enabling scripted performance analysis without UnrealInsights or the editor.

  • It depends only on Core, TraceAnalysis, and TraceServices, and decodes named stats, named counter time series, session diagnostics, frame boundaries, and CPU profiler scope events.

  • CPU scope events are buffered per (thread, specId) and flushed as grouped arrays to avoid per-event output for high-frequency scopes. The CLI supports filtering by logger, event name, stat/counter substring, and time range (--start-time / --end-time in seconds).

• Bump preferred MSVC to 14.50.

• Linux HWPGO support.

• Add Raw Pairs to TMap natvis.

• Expose a unique session identifier for each UBT invocation.

• Implement the UAT "-CompileOnly" command line option already documented in the usage info. It will compile all out-of-date script modules before exiting without running any command.

Bug Fix:

• Unreal Build Tool

  • Fix Dynamic Debugging LiveCoding Interaction.

  • Fix sln icon in the shell not displaying vs version, by removing empty first line in sln file.

• Fix ambiguous call converting method group to string.

• Fix RPC InputKey not processing Tapped inputs The Tapped parameter was previously omitted from the RPC arguments dictionary. Created conversion method "AsRpcArgs()" to automatically include all properties decorated with JsonPropertyName, eliminating the possibility of forgetting parameters.

• Make UpdateLocalVersion commandlet write P4 CompatibleChangelist into Build.version.

• UHT: Fix format string when usage in member declaration detected without an alternative, in UhtIssueBehavior.AllowAndLog case.

• Make UAT and UBT out-of-date DotnetDepends checks more robust when launching multiple instances on Windows. The tools themselves check a mutex, but the bat files could previously try to rebuild a tool by before that point.

• Mitigate race condition in ImmediateActionQueue.

• Fixed C# P4 BatchedCommand helper calculating the wrong length and overflowing the 32,699 character limit It wasn't taking into account the length of the base Command or GlobalOptions, which are also added to the arguments when running p4.exe.

Horde

New:

• Horde

  • TokenConfig ClientId and ClientSecret can be read from a Horde secret during configuration load.

  • Added OptionalRequires attribute for BuildGraph nodes. Allow nodes to declare dependencies using the new OptionalRequires attribute, which allow a dependent node's execution to continue if the artifacts failed to be created.

  • When assigning a job lease to an agent check if the required free disk space is available, otherwise assign a conform lease to the agent instead.

Bug Fix:

• Horde

  • Normalize IPv6-mapped IPv4 addresses to plain IPv4 for compute IP comparison.

  • Fixed shelved changelists not being deleted during an agent conform.

  • Dispose the Perforce PoolConnectionHandle when there is an exception during login.

  • Fixed when an agent lease is cancelled by a user the step will complete and upload the logs.

Insights

New:

• Unreal Insights

  • Added keyboard shortcuts for "Find [Max Duration/Prev/Next] Instance" of a timing event in Timing view and Timers view. By default: /,. for [Max/Prev/Next] in selected time range and Shift + /,. for global search.

  • Unreal Insights users can now create time, time range, and event-based annotations in Unreal Insight traces. The annotation data is saved in a sidecar.ini file that can be shared. This feature is to help individuals and teams with the performance analysis of trace files.

  • Added "Go to Frame" (Ctrl+G) and "Go to Time" (Ctrl + T) modals to timing insights. Allows navigation to Render Frame, Game Frame and time stamp.

  • Sort the analysis modules by name when displaying them in the session tab.

• Send OnConnect events on it's own thread. Refactored how events emitted during OnConnect is handled. Events can now be marked as "MaybeImportant" to treat events as important (without retaining in memory) when emitted during OnConnect, but as regular events when emitted elsewhere.

• Added support for tracing through a secured SSL socket. This works slightly differently from the standard socket connection, as the receiving side is expected to connect to the tracing application. The secure connection supports three modes:

  • Self signed certificate and authorization code.

  • Known certificate authority and authorization code.

  • Pre shared key (PSK). Methods of making certificates and authorization codes available on the connecting application is not provided by TraceLog. This needs to be transferred out-of-band.

• Update UnrealTraceServer to v1.24. This adds basic crash handling, and fixes memory leaks and crashes.

• Added API to UE::Trace to expose IsTailing, which allows game code to know if the tail buffer is in use. #[review] [at]fn-perfdev-server Added API call UE::Trace::IsTailing which returns true if the Trace Tail Buffer is active.

• Added "snapshot hitches" feature. This feature relies on the stats system to detect hitches. When a hitch is detected a trace snapshot and screenshot is written to the Saved/Profiling/Hitches directory. Frames are dumped into a directory for each process instance. Start tracking hitches by using in-game console command `snapshothitches -start` and disable by using `snapshothitches -stop`. Requires some stat group to be active, like `stat default`.

• Allow for crashes to contain a trace snapshot. Use cvar "CrashContext.TraceSnapshotOnCrash" to enable and "CrashContext.TraceSnapshotOnCrashTailSize" to set size of tail data to be written. Currently only supported on Windows.

• Add support for controlling max size when writing the tail buffer.

• TraceController now exposes target capabilities.

• Small increase to the time resolution timing shown in insights (without this, values near the low end of the automatic range have almost no precision - e.g. appearing as 1.2s).

• Added OnClose event for when a trace connection is severed.

• Added a MessagingInsights plugin, enabling visualization of UdpMessaging message summaries and lifecycles within Timing Insights.

• TraceLog now automatically emits regular statistics about Trace performance. This can help to analyze problems with Trace performance. They are visualized as counters in Timing Insights.

• Add bandwidth and percent value types for graphs and counter stats.

• Add a "panic mode" for TraceLog. This is triggered if the block pool is full and the TraceLog (worker thread or end frame pump) cannot process data fast enough. When panic occurs the process can continue without being affected, but tracing is no longer reliable and cannot be used for the remainder of the process lifetime.

Bug Fix:

• Addressing several UI/UX bug fixes in the new annotation feature.

• Module names may not contain network names.

• Fix flickering for channel tooltips in the trace control widget.

• Unicast trace status and channel status messages to reduce Trace Control network usage.

• Removed trace started notification from the Editor that affected the trace data.

• Add base file for Insights settings to enable settings persistent in Editor.

Framework

New:

• Level Streaming Persistence (Experimental): Added opt-in support for persisting actor states in a map's persistent level, persisting actor destruction by re-destroying, basic actor respawning (non-time-sliced), and game code hooks. These new features are opt-in and configurable through Project Settings > Level Streaming Persistence.

• Add * and -> operators to TInstancedStruct for convenience.

• ITF: Drop any active mouse hover capture prior to calling `BeginCapture()`. Fix issue where terminating hover cleared the wrong owner field.

• JsonObjectGraph now properly encodes Enums that are being used as Flags.

• Dynamic Loading Range Scaling option in World Settings leading to quicker PIE startup on large maps.

• Add support for interfaces in FWorldConditionContextDataRef binding.

Bug Fix:

• Apply const to query functions that do not perform mutating operations, so they can be used on a const UPrimitiveComponent.

• Added tick unregistration logic to ULevel::ClearLevelComponents to make sure that when incremental unregister is not permitted, tick functions are still unregistered from actors.

• Fixed crash in UBT when reporting Engine Files error.

• Fixed a crash when editing an actor when instances of that actor exist in cleaned up UWorlds.

Deprecated:

• LigthWeightInstances code marked as deprecated.

AI Debugging

New:

• Trace Based Debuggers

  • Refactored and moved TraceSessionsManager from ChaosVD Main changes:

    • Settings are now Attributes to assign/bind when creating the manager.

    • Sessions manager creation now requires explicit references since this is no longer setup as a group of related singletons:

    • Debugger trace runtime module.

    • Engine-editor bridge.

    • Trace module (TraceServices::IModule modular feature)

    • FChaosVDTraceSessionDescriptor replaced by UE::TraceBasedDebuggers::FTraceSessionDescriptor.

    • Moved DataStream related types to (FSessionStreamStatsUpdater, IRemoteSessionDataStream, FDirectSocketStream, FRelayDataStream, etc.) under namespace UE::TraceBasedDebuggers.

  • Replaced recording flag by the ID of the application instance that requested the active recording.

    • Allow recording controls to filter out sessions from the dropdown.

    • Fix message traffic issue by sending the Pong message only to the sender of the Ping (i.e., no broadcast)

    • RewindDebugger controls now filters out other Editor sessions.

    • Fix session naming issue with multiple local editor instances: The session name can only be replaced by "Local Editor" by the process handling the Pong message and not when generating that message since multiple editors can handle it.

• Rewind Debugger

  • Updated FRewindDebuggerTrack::GetStepFrameTimeInternal to use a scrub info struct providing more information to derived classes in order to select the best scrub time to use when using the stepping forward/backward buttons. VisualLogger track now allow users to jump directly to frames with events (i.e., skipping empty frames).

  • Added settings to control the desired transport mode for remote connections.

  • Added a new button to open the folder containing analysis files and one to delete all utrace files in that folder.

  • Added new virtual methods for runtime extensions to register new message types and handlers for remote connections.

    • Added new log categories widget to enable/disable verbosity filtering during recording and control the verbosity of each category (note that the initial implementation populates the "known" categories from the analyzed data of an active recording)

  • Added explicit methods to handle the local session recording and made sure that this functionality doesn't interfere with the other active sessions.

    • When auto-record on PIE is used we make sure to select the local session in case multiple remote sessions are available. Same when resuming or advancing one frame in PIE.

    • Fixed issue where users are not able to start recording while PIE is paused.

  • Added Auto-Scroll functionality.

    • Playback controls are now always available and will disable auto-scroll.

    • Manual scrubbing will disable auto-scroll.

    • Recording started on PIE will activate auto-scroll.

    • Resuming recorded PIE session will reactivate auto-scroll.

  • Added analysis opened/closed notification for editor extensions.

    • Updated some editor extensions to use RuntimeExtension instead when it was the intent (e.g., controlling traces)

  • Added support for remote sessions provided by TracedBasedDebugger/Analysis modules.

    • Updated toolbar to use RecordingControls.

    • Removed SaveTrace command since analyzed sessions are saved to disk by default.

    • Converted VLog filters from checkbox to toggles to allow users to set multiple ones without closing the menu.

    • GameplayProvider no longer filters out Server worlds.

  • Restore previous VLOG recording state when stopping traces.

  • Implement per-provider locking for RewindDebugger trace providers and migrate all call sites from session-level locks to provider-level locks to prevent deadlocks.

    • Add FProviderLock implementation to FAnimationProvider, FVisualLoggerProvider, FPoseSearch::FTraceProvider, FUAFProvider, FAnimNextAnimGraphProvider, FUAFAnimNodeProvider, FChooserProvider, and FStateTreeTraceProvider.

    • Replace FAnalysisSessionReadScope with FProviderReadScopeLock at all RewindDebugger track call sites (~60 files).

    • Replace FAnalysisSessionEditScope with FProviderEditScopeLock in all trace analyzers.

    • Replace Session.ReadAccessCheck()/WriteAccessCheck() with provider-level ReadAccessCheck()/EditAccessCheck().

    • Add missing ReadAccessCheck/EditAccessCheck to provider methods that were unprotected.

    • Optimize lock scopes to minimize hold time (cache data inside tight locks, move widget creation/asset loading outside).

    • Wrap Session.UpdateDurationSeconds() calls in FAnalysisSessionEditScope where needed.

  • Add configurable allowed class types filter to the Rewind Debugger target selector Replaces the hardcoded ULevel/UWorld child filter in the object selector dropdown with a configurable allowlist of class types.

    • Adds a new URewindDebuggerProjectSettings class (project-scoped, saved to RewindDebugger.ini) with a SelectorAllowedTypes array, defaulting to AActor.

    • Extends URewindDebuggerSettings (user-scoped) with a matching SelectorAllowedTypes array that can add types on top of the project settings but not override them.

    • The selector now filters by checking IsSubClassOf against the combined allowed types; an empty list falls back to allowing everything.

    • Renames URewindDebuggerSettings display name to 'Rewind Debugger (user preferences)' and fixes VLog settings to use its own localization namespace to avoid collision.

• Visual Logger

  • Introducing new defines to split functionalities: Recording, Rendering and Visualizer Tool.

    • UE_DEBUG_RECORDING_ENABLED: Indicates whether the UE_DEBUG_* macros will record the element (VisualLogger and/or insight traces).

    • UE_DEBUG_RECORDING_USING_VLOG: Indicates whether the UE_DEBUG_* macros will use the VisualLogger recording process to store entries and write to all registered output devices. Otherwise only insight traces are used.

    • UE_DEBUG_RENDERING_ENABLED: Indicates whether the UE_DEBUG_* macros will use immediate debug draw visualization.

    • UE_DEBUG_VISUALIZER_TOOL_ENABLED: Indicates whether the analysis of the recorded data is active and dedicated UI and tools should be compiled.

    • To maintain compatibility ENABLE_VISUAL_LOG will enable all three functionalities. Without UE_DEBUG_RECORDING_USING_VLOG we bypass most VisualLogger functionalities to log to the trace directly. Examples of disabled features:

      • CategoryAllowList

      • NavigationDataDump

      • DebugSnapshot

      • ClassAllowList

      • ObjectAllowList

      • Output devices.

  • Added opt-in functionality to apply LogCategories verbosity filter when recording. Can be controlled by:

    • Console commands: Vislog.ActivateVerbosityFilterWhenRecording and vislog.DeactivateVerbosityFilterWhenRecording.

    • Config Property `bUseVerbosityFilterWhenRecording` in VisualLoggerSettings.

• IMessageBridge

  • Add IsSubscribed(FTopLevelAssetPath) pure virtual to the base IMessageBridge interface so any bridge implementation can report whether it forwards a given message type.

  • FMessageBridge (standard) returns true unconditionally (PATHNAME_All).

  • Add FOnSupportedMessageTypesChanged multicast delegate, broadcast whenever the supported message types list changes (from RegisterExternalSupportedMessageType, InitializeMessagingSystem, or any path through ReInitializeMessagingSystem).

  • Add SetMessageBridge() to store an external bridge reference for per-type reachability queries.

  • Add CanPublishToNetwork that checks for a standard bridge (INetworkMessagingExtension modular feature) or queries the custom bridge's IsSubscribed for the specific type.

  • Gate SendPong on CanPublishToNetwork<FSessionPong>() to prevent ghost sessions when no bridge can forward Published messages back to the controller.

• SmartObjectComponent Uses GetActorDescProperties.

Bug Fix:

• Rewind Debugger

  • RecordingStarted is now called immediately once the connection gets established (not deferred to game thread) since the channels need to be enabled before the next game thread frame to not miss events.

  • Made sure that world times got reset before enabling trace channels from OnEnableRequiredTraceChannelsInternal virtual method.

• AI Blueprint Helper: Updated CreateMoveToProxyObject to make sure the controller is still a valid Actor that can be stored in a weak pointer.

• Visual Logger: Updated trace output device to handle entries larger than the maximum trace event size.

• Fix: GetSmartObjectBounds was getting the owner actor transform instead of the component one.

• Gameplay Debugger Replicator fixes to work with the MultiServerProxy. Gameplay Debugger Replicator used indices to replicate (which wouldn't necessarily match the other server). Now using names when available, Extensions are still by index.

• Config: Added ensure and recovery code when a config is created and the 'config' specifier is missing on the UProperty.

AI EQS

New:

• Added the bStripFromClientBuilds option to UEnvQuery, mirroring the pattern on UDataTable. This allows EQS assets to be excluded from client builds, since they are server-only AI queries.

AI Navigation

New:

• Mass Navigation

  • Added OffsetCornersFromBoundaries parameter to FMassNavMeshPathFollowTask to push wall-hugging corners away from walls.

  • Improved Mass navmesh path-follow end-of-path detection with combined distance and projection checks; also fixes a division-by-zero.

  • Added FAgentHeightFragment to additional Mass StateTree tasks (FindSmartObjectTarget, NavMeshPathFollow) that need a height to query the navmesh.

  • Added FAgentHeightFragment requirement to FMassNavMeshFindReachablePointTask so it can build a valid FNavAgentProperties for queries.

• Nav Mesh

  • Optimized Detour navmesh link memory by sizing the base link pool to actual usage (~30 MB savings on large maps); exposed bMinimizeLinkPoolSize and added link utilization stats to DumpNavMeshMemory.

  • Optimized navmesh vertex storage by packing vertices as tile-local float offsets (~50% memory reduction on vertex data); navmesh version bumped to 28 with automatic legacy-format upgrade on load.

  • Fixed misleading description and tooltip on ARecastNavMesh::bForceRebuildOnLoad.

  • Exposed ARecastNavMesh::AverageLayersPerTile and reduced its default value, saving memory in the tile pool allocation.

  • Skipped BVTree creation for navmesh tiles with very low polygon counts to save memory.

  • Added bDrawOnScreenInformation on ARecastNavMesh to toggle on-screen detailed navmesh information.

  • Optimized FRecastNavMeshGenerator::RemoveTiles to reduce a hang when many tiles are dirty simultaneously.

  • Nav Area:Nav Mesh: Added per-mesh custom NavArea support on UNavCollision (bUseSurfaceArea + AreaClass) so static meshes can apply custom walkable area costs during rasterization.

• Navigation System

  • Change to how Pawns without a PreferredNavData set work. This makes it so, if unset, that the Pawn will now only find and use NavData with matching CanFly values. This prevents ground-based Pawns from trying to use flying navigation data.

  • General navigation log improvements (clearer messages, better contexts).

  • Added diagnostic logs on AddNavigationSystemToWorld, OnWorldInitDone, GetWorldBounds, PerformNavigationBoundsUpdate, OnLevelAddedToWorld and ANavigationData bound changes.

• Avoidance: Added configurable side-bias threshold and right-side passing bias to Detour crowd avoidance.

• Added logs that record AsyncLoadLock state and increased verbosity in navigation tests to help diagnose intermittent failures.

• Added the navdata name to navdata registration logs. Added a log when navigation building is prevented by a navigation lock.

• Navigation: Exposed GetLengthFromPosition to Blueprints.

• Removed UE 5.5-era deprecated navigation code.

• Mass Avoidance: Mass avoidance gameplay debugger can now display entity radius when no collider is present.

• UEFN now dirties the package on navigation generation completion so changes can be saved.

Bug Fix:

• Navigation System

  • Fix data race in RegisterNavRelevantObjectInternal when using async nav data gathering. When bDoFullyAsyncNavDataGathering is enabled, FRecastTileGenerator::DoWork() runs on a worker thread and reads FNavigationElement fields via FNavigationRelevantData::SourceElement (a TSharedRef<const FNavigationElement>). Concurrently, the game thread can call RegisterNavRelevantObjectInternal (e.g. when a component is registered a second time) which overwrites the same FNavigationElement in-place through a mutable TSharedPtr. The root cause is that the repository stores TSharedPtr<FNavigationElement> (mutable) and overwrites in-place, while all other holders (navigation octree, pending updates, tile generator) hold TSharedRef<const FNavigationElement> to the same heap object, assuming immutability. Fix:

    • RegisterNavRelevantObjectInternal now allocates a new FNavigationElement and replaces the map entry via Emplace, instead of overwriting *ExistingElement. The old instance remains alive and unchanged as long as the octree or an in-flight tile generator holds a reference to it via SourceElement.

    • F Navigation Octree Controller::RemoveChild now compares children by FNavigationElementHandle (UObject + SubElementId) instead of TSharedRef pointer identity. This ensures that passing a newly-allocated element for the same navigation object correctly finds and removes the old entry from OctreeParentChildNodesMap.

  • Fixed reentrance in UNavigationSystemV1::RegisterNavData that could trigger when registration callbacks spawned new nav data.

  • Now waits for initial async loading to complete before triggering an automatic rebuild; new bWaitForAsyncLoadingBeforeBuildingNavigationAutomatically property controls the behavior (enabled by default).

• Navigation

  • Fixed an intermittent issue where off-mesh connections could be missing after navmesh generation, depending on the order tiles were processed.

  • Fixed an issue where deleting the last NavMeshBoundsVolume in a level could leave the navmesh in a null state, causing subsequent property edits to trigger an ensure. The navmesh is now preserved when there is no longer anywhere to build navigation, and any stale tile data is cleared instead.

  • Fixed an issue where traveling to a level that had a navigation bounds volume but no saved navigation data would leave the navmesh empty, preventing NPCs from pathfinding. The navigation system now correctly triggers an async rebuild when it spawns fresh navigation data at runtime.

  • Fixed an issue where NavLinkProxy actors used by Child Actors did not work correctly on startup in Play in Editor.

  • Fixed an issue where area costs were not set before NavLinks were snapped during level serialization.

  • Fixed an issue where a NavLink Proxy could fail to register when the navigation system was not yet initialized.

  • Fixed several issues with directional generated NavLinks:

    • Fixed an issue where generated NavLinks were not applied to the correct layers when directional links with different areas were present.

    • Fixed an issue where directional NavLinks were not height tested.

    • Fixed an issue where reversed NavLinks were stored incorrectly. Directional up links are now stored in reversed order to keep them with their associated down link, and the owner position is now correctly validated to be contained by the tile when handling asymmetric border sizes.

  • Fixed an issue where the AllowLinkGeneration console variable was not enforced uniformly across all navmesh generation paths.

  • Fixed an issue in Recast where generated data was not placed where the caller expected it.

  • Fixed an issue where EncompassesPoint did not work correctly on ANavMeshBoundsVolume.

  • Fixed an issue where spline points were generated in world space instead of local space, causing the world transform to be applied twice.

  • Fixed an issue where a component could remain in the navigation octree after being unregistered.

  • Fixed an issue where navigation bounds were not cached correctly before being registered, which could trigger an ensure.

  • Fixed an issue where undoing or redoing changes that required a navmesh rebuild were not being detected correctly. The navmesh now responds to PostTransacted notifications to catch these changes.

  • Fixed crash in AddNavigationSystemToWorld during Sequencer undo/redo on transient worlds.

  • Crash Fix: [Navigation] Fixed a crash that occurred when an extreme JumpLength value was set in a NavLinkJumpConfig. The inflated tile border size could cause an allocation failure or integer overflow during navmesh generation. A warning is now logged when the border size exceeds the tile size, and tile generation is safely aborted if the heightfield size would overflow.

  • Fixed ensure when editing NavigationSystem config properties in Project Settings by skipping CDOs in FEditorViewportClient::OnObjectTransacted.

• Nav Link

  • Fixed multi-config registration for generated navigation links.

  • Fixed an ensure in ComputeCustomLinkBounds.

  • Fixed crash in ANavLinkProxy::GetComponentsBoundingBox.

  • Fixed an ensure that triggered when undoing a NavLinkJumpConfig change that had a LinkProxyClass set.

• Nav Mesh

  • Fixed navmesh loading quantization factors not matching newly-updated CellSize settings (occurred when settings were changed via config files outside the editor).

  • Detour dtNavMeshQuery::queryPolygons now handles out-of-memory conditions gracefully.

• Newly created Blueprint NavArea classes are now registered via PostCDOCompiled so they take effect without a reload.

• Automated Testing: Fixed an issue where AutomationLoadMap started Play in Editor immediately after loading a map, copying an empty navmesh into the PIE world before the async editor rebuild could finish. PIE startup is now deferred until the editor navmesh finishes building.

• Fixed multithreaded access on FLandscapeHeightfieldCollisionComponent::CachedHeightFieldSamples reachable through INavRelevantInterface::GatherGeometrySlice.

• Prevented a crash when exporting geometry containing too many triangles for navmesh generation.

• Fixed navigation data not being removed when using One File Per Actor (external actors).

• Fixed "Build > Build All Levels" leaving the navigation system in a broken state.

• Fixed navmesh being out of sync with unloaded objects in World Partition maps when Build Paths is run.

• Ensured the map package name is known before building a World Partition navmesh in the editor so the map can be reloaded afterwards.

• Fix FCompositeNavModifier::CreateAreaModifiers not taking into account FKSphylElem internal rotation Fix FCompositeNavModifier::CreateAreaModifiers not using the proper length for a FKSphylElem Fix FAreaNavModifier cylinder constructor not handling non vertical cylinders. This will now fallback to a box if the cylinder is not vertical.

• Fixed ai.debug.nav.DirtyAreaAroundPlayer debug command not working on the server.

AI State Tree

New:

• State Tree

  • Property Binding Utils:

    • Added a cvar to control automatically removing failed-to-resolve source binding path bindings or not for State Tree. Default true(old behavior). Missing target struct binding path bindings or failed-to-resolve invalid target binding path bindings will always be removed automatically. Missing source struct binding path bindings will never be removed automatically.

    • Fix up State Tree Editor Bindings when UserDefinedStruct, Blueprint, or UObject gets reinstanced from live coding. Cache dependency to filter out state tree assets.

    • Correctly gather dependent structs for compiled property bindings.

    • Use struct's authoraritive version when resolving indirections.

    • Bindings display friendly name for UserDefinedStruct properties.

  • Added option to override start state by gameplay tag when starting running the tree. States corresponding to the same gameplay tag will be searched through in breadth first order.

  • Do not create an instance data storage for shared instance data when no shared data exists. It reduces the runtime memory footprint. Each thread that access state tree increments a counter. That counter is static and is valid for all state tree assets. That means each state tree asset uses a ?number of threads? amount of storage, even if the state tree asset is not intended for threading.

  • Add a queue and asynchronous state tree compilation. The compilation is always on the game thread. The state tree asset is compiled "just in time" the first time it is used by the game. The features are disabled by default.

    • With cvar StateTree.Compiler.EnableQueuedCompilationOnAssetLoad, the public step will be compiled synchronously when the asset loads, and the internal steps will be queued for later. Without the cvar enabled, the previous behavior is maintained. The compilation of the public and internal steps are compiled synchronously.

    • With cvar StateTree.Compiler.EnableQueuedCompilationWhenAssetDirty, the asset is queued for compilation as soon as it is modified in the editor.

    • With cvar StateTree.Compiler.EnableCompileSynchronouslyInPIESession, all queued assets are compiled synchronously before a PIE session starts. While in PIE, assets will not be queued. They are compiled synchronously.

    • With cvar StateTree.Compiler.NumberOfQueuedCompilationPerBatch, you control how many state tree assets compile per ticking loop. To deactivate, set to 0. Every tick, the engine will compile NumberOfQueuedCompilationPerBatch queued state tree assets, including the dependencies.

  • Refactored and fixed incorrectly accessing subtree parameter, global parameter and global instance when it exists in a parent frame multiple levels above.

    • Now we cache corresponding Parent Frame IDs for accessing global parameter and global instance in temporary data, and cache corresponding index base for accessing global parameter and global instance in active instance data.

    • No longer sets Subtree and Global Parameters in UpdateInstanceData because they have already been set when creating the frames and they don't change. We update ActiveInstanceIndex, GlobalInstanceIndex and GlobalParameterIndex in UpdateInstanceData.

  • Enable evaluation scope by default. Tell the cooker about the cvar that can affect the compilation result.

  • Implement EvaluationScopeInstanceData for condition's EnterState/ExitState/StateCompleted.

  • Remove STATETREE_POD_INSTANCEDATA in favor of UE_STATETREE_CONSTRUCTED_TRIVIALLY_COPIED_NO_DESTRUCTOR_INSTANCEDATA or UE_STATETREE_ZEROED_TRIVIALLY_COPIED_NO_DESTRUCTOR_INSTANCEDATA. Properties that are initialized in-place need the constructor. ScriptStruct instances constructed from script (BP or StateTree instance data) are memset to 0 by default. The POD has a different meaning in C and CPP (pre 2020). It is preferable to use the more descriptive term "trivial" to identify types that can be trivially constructed and copied.

  • Allow creating new StateTree assets from linked asset dropdown.

  • Create UE::StateTree::EComparisonOperator to replace EGenericAICheck from the AIModule. This is an effort to make StateTree not depend on AI modules and make it generic for everyone to use.

  • Implement drag and drop for state tree state nodes Extending the existing drag and drop structure to support dragging state's nodes around. By default, dragging a node moves it to another state (literally moving) keeping the bindings valid if any other node references it's properties. By holding Ctrl key while dragging, the behavior alternates to copy instead move.

  • Added FStateTreeExecutionContext::GetCurrentlyProcessedStateSelection.

  • Prevent linked state override when bindings could use invalid data.

  • Hide utility consideration when they are not usable. The parent needs to have a selection behavior that uses them.

  • Access ExecutionRuntimeData from async task.

  • Add a color bar that matches the category color.

  • Chained Property Ref from multiple parent frames above can now correctly fetch source data. Now we fetch the associated parent frame that stores GlobalParameter or SubtreeParameter by FrameID.

    • Disabled using PropertyRef in ExternalGlobalParameterData.

    • Deprecated and refactored FindFrame.

    • Deprecated and refactored FStateTreePropertyRef::GetMutablePtr.

    • Deprecated StateTreePropertyRefExternalHandle.

  • Execution context uses a view instead of the property bag. Deprecated the property bag version. This is a step to use a permanent script struct instead of the transient property bag.

  • Add menu action to select the transition's target state.

  • Add new transition targets. Parent, NextParent, and NextSelectableParent. They are reconciled at compile time and work similar to NextState and NextSelectableState.

  • Added a button to remove all elements from the tasks, evaluator, condition, transition lists.

  • Added a button to remove all properties from the property bag.

  • Move the temporaries before it is used in EnterState. Previously, they were all moved in UpdateInstanceData. It caused a problem if an async task requested the instance data before the state was added to the Frame. Usually, that could not happen, but global nodes (task and evaluator) can be started temporarily. Their EnterState is called, and they will only be added to the frame when the linked state is added.

  • Add a global callback and a callback on the editor extension to validate the state tree asset. The validation occurs when the asset loads, and before it compiles. The user can use the callback to modify the editor data before the asset compiles.

  • Add a condition to compare a single Gameplay Tag against another.

  • Capture condition / task / utility names in ST rewind debugger.

    • Add IStateTreeDebugInfoProvider to provide editor data driven debug info when possible, with default runtime only debug info as fallback.

  • Add ability to mark a transition for reselection.

• Added Experimental State Centric View.

  • Disabled by default. Enable via `StateTree.Editor.Experimental.EnableStateCentricView`

• Show number of enter conditions / tasks / transitions / considerations / parameters in details header.

  • Also show utility weight if it's just a weight.

Bug Fix:

• State Tree

  • Recursively Trigger transitions from parent frame when a subtree completes. This solved issues caused by When hit the max iteration, the execution context will lose track of info in the next frame when continuing transition processing from the subtree completion.

    • Added unit test to verify this.

  • Fixed an issue where events are not visible to the state required event to enter from on completion transition. Fixed an issue when a subtree completes, broadcasted delegates and events will be incorrectly cleared.

  • Remap state event IDs when cut/paste states Preserve and remap state event IDs during copy/paste to fix compilation failures when a pasted state has nodes that bind to required events on the state's enter conditions.

  • Fix crash in Enum Compare Condition when resetting right field default value.

  • Events added during TriggerTransitions will be queued and only reset in the next TriggerTransitions. This allows multiple parallel trees to share event with each other, and fixes events sent in task on enter won't be accessible in the next tick in parallel trees.

  • Prevent Linked Asset override at runtime when the Linked State Parameter is binding source or binding target. This includes the parameter is bound to something else, a node is bound to the parameter or a node's appended property function is bound to the parameter.

    • Use an additional flag for override. Cache the flag during Compile for runtime check.

  • Disabled Promote to linked state parameter option.

    • Fixed an issue where property cannot be promoted to state parameter if state parameter is empty.

  • Disable promoting to state parameters if the state is a linked state.

  • Correctly Scope Start and Stop global tasks debug phase. Global tasks are entered/exited hierarchically and each frame should have its own scope to reflect the correct ordering.

  • Fixed an issue where transition delegates weren't triggered if the delegate was broadcasted during the transition tick.

  • False positive circular reference while compiling state tree asset async. This occurs when A refers to B and C. And B also refer to C.

  • Fix issue with override linked asset when the state needs reentrance. It used to pick the new override for sustained transition instead of picking the previous override. Add unit test for 2 repro of that same bug.

  • Make status not trivially copiable. The inner pointer might point to itself. Unreal container do use trivially allocated structure. They do not call the move or copy constructor.

  • Fixed states order is reversed when inserting before another state in the editor.

  • Remove the temporary instance data once it has been consumed. Previously, all temporary instance data was moved in UpdateInstanceData. Now, they are only moved when the task starts.

  • Only append temporaries when they will not be copied later in Enter. This fix issue introduced with.

  • Add callback to get the asset registry tags from the editor data. Use the editor schema to always have a valid schema in case the compilation fails.

  • State Tree Debugger: Added support for breakpoints in statically linked assets (i.e., not dynamic overrides).

    • Asset no longer get dirty when adding/removing breakpoint.

    • Select the first available instance in the debugger view when analysis starts.

  • Property Binding Utils:[State Tree] BindingView rework.

    • Added error icon for Missing struct.

    • Added error icon for binding path failed to resolve.

    • Click on Binding struct will traverse to the corresponding struct property row.

    • Click on Binding path will traverse to the corresponding property property row.

• Fix issue where we use stale linked state tree override whenever there is a change overrides in the middle of the current context's execution Since we are only allowed to set linked state tree overrides before we start context's execution, it is not possible to update it when an override changes sometime between the start and the end. To fix this we use a delegate to fetch current state tree overrides from external source.

• Fix rename failing on to be discarded ST editordata schema object.

Blueprint

New:

• Blueprint "enable/disable" node submenu options moved out of experimental. Right-clicking on a node with exec pins will now present options to enable or disable the node, without having to opt-in to this behavior.

• Blueprints: Make FVector2D default values work when exposed on spawn on the Construct Object BP node.

• Added simple counter to ensure if too many Blueprint async actions are created. The number of allowed actions can be set using the console variable `bp.MaxAsyncActionCount`. Set the number to <= 0 to disable the ensure.

• The Blueprint editor scripting API has been greatly expanded. For editing Blueprint graphs use the new BlueprintGraphEditor. For general Blueprint editing see the new functions in BlueprintEditorLibrary. If you're unfamiliar with these APIs consider running help(unreal.BlueprintGraphEditor) or help(unreal.BlueprintEditorLibrary) in your python console.

• Expose FPerPlatformBool to Blueprints to match Int and Float.

• Find in Blueprint: Will now search keys in the default key-value pairs in Blueprint Map variables. Previously only Map values were searchable.

• Struct Utils: Add helper functions to generate a UserDefinedStruct from a property bag. Property Bag are great when used internally the same package. It can cause issue when there's a reference outside the package. UserDefinedStruct are better at handling those.

Bug Fix:

• Fixed Blueprint function local variables being allowed to have the same name as member variables, which led to default value inheritance problems. Name validation is properly applied now when naming local variables. Name collision was already properly checked for member variables.

• Fixed crash when loading Blueprints with ComponentClass overrides.

• Fixed crash when deleting a character Blueprint and anim Blueprint at the same time.

• Fixed crash when pasting a component into a Blueprint.

• Fixed ensure when changing the class of a scene component.

• Structure assets will no longer causes crashes if deleted when they are used as member variables in Blueprints.

• Change K2Node::GetBlueprint to possibly return null (expected by most callers), and add GetBlueprintChecked for the old behavior.

• Fix several Blueprint editor crashes that would happen when recompiling at an unexpected time.

• Fix crashes when trying to reparent a Blueprint to a temporary class like a python wrapper, these are no longer shown as an option.

• Fields and properties associated with transient, non-native uclasses are no longer shown in the Blueprint context menu, as when placed in a graph they will not be able to resolve themselves when the asset is loaded.

• Fixed issue looking up default values for the root component when it is named DefaultSceneRoot.

• Fixed crashes in FBlueprintActionFilter::IsFilteredByThis.

• Component reference picker improvements: Allows picking components in the Blueprint editor.

• Fixed one cause of the prolific "PinHelpers::UnresolvedPins.Num() == 0" warning message.

• Fix bug where drag and drop could create an invalid floating point node.

• Nested split pins no longer cause data loss or assertion failure when their backing schema (Struct or Function) is changed.

• Correctly warn about trying to delete in-use local variables.

• U Subobject Data Subsystem::AddNewComponent will no longer crash when adding components without an explicit Blueprint context.

• Component subobjects tagged as RF_ArchetypeObject now have their subobject flags conformed, forcing RF_Public and consequently preventing 'linked to private object' error.

• U Blueprint Editor Library::GetBlueprintAsset now looks for adjacent UBlueprint objects, e.g. if a Level asset is provided as the object to get the UBlueprint from.

• Fix issue where properties like skeletal mesh would be reset after Blueprint duplication.

• Fix several editor crashes when trying to load invalid Blueprint assets.

• Fix crash when trying to set a local variable named the same as a replicated property.

• Fix issue where copy-pasted Blueprint nodes would no longer be pure.

• Fix bug where data assets made from Blueprints had the NativeClass asset registry tag set to the Blueprint instead of the parent native class. This will be fixed the next time those assets are resaved.

• Fix bug where undoing a child actor component deletion could create duplicate actors.

• Fixed a bug where changing a UUserDefinedStruct used in an FInstancedStruct property of a UDataTable row, would not re-instance the structs (as they do in non-UDataTable cases), causing data table details panels to crash trying to read new fields in the now-outdated instance memory.

• Fix missing native/instanced struct value data on runtime-spawned BP actor types with "Generate optimized Blueprint component data" enabled.

• Fix bug where Child Actor Class could not be set back to none in child actor components.

• Fixed Blueprint default properties with custom property customization not using the correct IsEnabled value in certain cases.

• Fix crash trying to compile a variable set mode pasted from another class.

• Struct Utils: Fix dirtying and recompile property bags when a UserDefinedStruct is modified.

• Fix Set Fields Blueprint node to accept non-const reference parameters.

• Output pins on Blueprint result nodes are once again validated for uniqueness when being edited.

Blueprint Compiler

Bug Fix:

• Blueprints are now compiled in the order their class taxonomy will define, rather than the one they currently define - this fixes crashes when compiling Blueprints after changing their parent class.

• Macro nodes no longer raise unsupported Blueprint changed notifications during compile, fixing crashes when compiling some Blueprints with complicated macros.

• Blueprints loaded for diffing will no longer attempt to compile before PIE, even if they have been marked as dirty.

• Guard against potential attempts to reinstance non-Actor objects with an invalid outer.

• Fixed rare non-determinism in Blueprint generated bytecode caused by text values that matched their default string.

• Blueprints that are in a dirty state because they are using a Struct that has been modified are now automatically recompiled on save.

• Fixed rare crash when compiling Blueprints with invalid functions.

Blueprint Runtime

Bug Fix:

• TScriptInterface now only produces a valid value if the provided object implements the specified interface (either as a Blueprint class or natively).

• Fix race condition between UPrimitiveComponent::Postload and FObjectInitializer::InitProperties when instantiating a BP while its CDO is completing its initialization on the Gamethread.

Gameplay

New:

• Input

  • FInputDeviceScope refactor and deprecation.

    • Deprecation the FInputDeviceScope type. Instead, you should use the new FInputDeviceRegistry type instead. This registry is thread safe and removes the need for Input API's to wrap every event with a FInputDeviceScope, which is very error prone and confusing.

    • The FInputDeviceRegistry should be populated any time a new device is *connected*, and has an assigned FInputDeviceId. This way, the device name/type is evaluated once, upon connection, instead of every single tick.

    • Effectively make the FInputDeviceScope no-op unless the UE_USE_LEGACY_INPUT_DEVICE_SCOPE define is set to 1. Users can define this in their Target.cs file if you still depend on FInputDeviceScope.

    • For forward compatibility, when a device is connected (IPlatformInputDeviceMapper::Internal_MapInputDeviceToUser is called) if there is not already a new device registry entry available, we will attempt to populate it from a device scope that is available.

    • Enforces a better contract for the FInputDeviceId to each platform and makes them all consistent.

    • Linux and Mac were completely missing FInputDeviceScopes, and they now have a FInputDeviceRegistry call to resolve that.

    • In CommonInput and the Input Device Subsystem, utilize this new FInputDeviceRegistry instead of FInputDeviceScope's. The names of the types for common input should be the same, and do not require asset updates. Same with the hardware device identifiers.

  • Add some debug data to player input available in non-shipping and test builds behind the UE_PLAYER_INPUT_INCLUDE_DEBUG define.

• Mover

  • Updated README documentation, accounting for bugfixes and feature set changes.

  • Populating/refreshing shared settings in OnRegister of a Mover component so we guaranteed have valid shared settings.

  • Reworked kinematic simulation to be separate from MoverComponent, as a stepping stone towards using Mover with non-Actors.

  • Removed unsupported PhysicsMover / NetworkPhysicsLiaison code from Mover plugin, in favor of ChaosMover plugin.

  • Support perching radius threshold so characters can be configured to fall off ledges if they're only partially supported.

  • Add MixMode parameter to Play Mover Montage BP node, for control of how the root motion mixes with other movement sources.

  • Added a BP-friendly method of querying for the floor so it's easier to include in Blueprinted movement modes.

  • Exposing the movement base's transform deltas through an update event, in support of motion matching while on a moving platform.

  • Implementing MovementInterface on UMoverComponent and using the interface in encroaching checks so we also use the movementcomponent path and properly check encroachment when using a mover component.

  • Evaluating Mover instant effects after modifiers are added/removed. This helps crouch apply properly without any depenetration. Also adjusting the stance modifier to always adjust capsule location when modifying capsule size.

  • Add residual velocity when leaving a movement base.

  • Reworked kinematic based movement to eliminate drift on rotating, tilting platforms similar to heaving boats.

  • Adding a projection setting to nav walking modes that allows users to specify what geometry to project to in relation to the navmesh. Also adding proper support for move off navmesh option for NavWalkingMode.

  • Adding an ensure to navwalking modes noting that the bAllowClientSideNavigation navigation system setting needs to be true if nav walking mode is running on a client so a navmesh is available for nav walking to use. This is the case when running a pawn in nav walking mode with Fixed Tick Forward Predicted Network prediction simulation.

  • Added helpers for common rollback blackboard entry creation cases, and current-frame-only persistence option.

  • Added simulation context as a parameter to core Movement Mode functions.

  • Added query for the next anticipated movement mode.

  • Adding RVO interface to NavMoverComponent to support detour crowd avoidance. Note, this is not force based RVO avoidance. Also adding some example content to mover examples to show this functionality.

  • Remove unnecessary falling check that will never get hit in movement utils.

  • Added prediction mode support for the rollback blackboard, so trajectory prediction flows can read/write with it without affecting the true simulation state.

  • Add USimpleFlyingMode to simplify the process of making a Blueprint driven flying mode.

  • Made all default movement modes function with non-capsule shapes as long as they're reasonably symmetric within the movement plane.

  • Added support for single-entry values in the rollback blackboard, along with a policy to ignore rollbacks.

  • Mover, ChaosMover: Added more time step information to event data, allowing differentiation on factors like whether a resimulation is occurring.

  • Mover, ChaosMover: Added more contextual information to time steps and events.

  • Network Prediction and Mover: Expanded ShouldReconcile to allow the option of deferring to a simulation driver function.

  • Mover Examples: Adding example map to help test scaling to larger NPC counts.

  • Add Mover Methods to query if a tag exists. Add Mover FSM nullptr checks.

• Level Streaming Persistence Plugin

  • Exposed persisted property configuration to editor as DeveloperSettings.

  • Exposed the LevelStreamingPersistenceManager's SerializeTo and InitializeFrom functions to Blueprint. SerializeTo now updates persistence data for visible levels, ensuring that the in-memory cache is up to date for all levels of the map before serializing to a binary blob.

  • Now shows warning in editor when a persisted property is missing editable specifiers.

• GAS

  • Add RemovalPolicy to OnApplicationGameplayEffects, incorporated in AdditionalEffectsGameplayEffectComponent.

    • Use case: Control life time of external applied GE through GE that applies it conditionally. I myself have noticed this before, and I've seen bugs in the past from designers not understanding that a GE applied through a GE controls its own lifetime by default, they implicitly assume it will be removed when the effect which applies ends.

    • Added support for removal policy, following a very similar pattern to Granting GAs through a gameplay effect component (You can cancel / end the GA when the GE granting the ability is removed).

    • Added EGameplayEffectGrantedEffectRemovalPolicy enum (GrantedEffectControlsOwnLifetime, RemoveGrantedEffectOnEnd).

    • Added stack count to remove field to conditional gameplay effect.

    • OnActiveGameplayEffectRemoved removes any on-application effects whose policy is RemoveGrantedEffectOnEnd.

    • Added content validation: Error if RemoveGrantedEffectOnEnd is used with an Instant owning GE or an Instant granted GE Updated AdditionalEffectsGameplayEffectComponent to support controlling lifetime of granted GEs.

  • FActiveGameplayEffectHandle now holds a reference to its Owning AbilitySystemComponent rather than using a Global Map.

• Remote Objects

  • Introduced AActor::GetPreferredRemoteServer to allow Actors to migrate together (e.g. Controller depends on Pawn's Location).

  • Fixes that allow parts of the AbilitySystemComponent to work with object migrations and multi-server proxy.

• Cameras

  • Make playback mode only affect whether a GPC component writes to the output component Don't make it affect whether a standalone camera system is created or not. This makes it easier to manage, and easier to understand for the user.

  • Some errors and warnings shouldn't be reported when running editor previews.

  • Rename AutoActivateForPlayer to DefaultPlayer, and simply always use that unless anything else is specified.

  • Add "playback mode" to the GPC components This allows GPC components to be recorded by Take Recorder. The output camera component is also recorded, and upon playback, the new "playback mode" option can be enabled (similar to how physics should be disabled on recorded actors). This lets the output camera component be animated by the recorded keyframes, without the GPC system interfering.

  • Add a sprite icon to GPC components This makes it easier to locate the GPC component in the scene when the output camera is offset from it. The sprite is hidden when the output camera is close or on top of the root location.

  • Allow using an "output" camera component created in the parent actor.

    • Actor components cannot create visible/editor-friendly children components themselves. Component hierarchies need to be created by the actor. This change moves the creation of the "output" camera component to the parent actor.

    • The GPC component only creates it if they can't find one created by the actor, which can happen if the GPC is inside another actor who doesn't know about all this, such as a character pawn or any other Blueprint. The user can still get this output camera component to be visible by creating it themselves and parenting it under the GPC component.

    • Since this effectively changes the output camera component from a "hidden" implementation detail to an "official" component of the actor, it would now show up in the Details View of the actor by default, cluttering up the UI with irrelevant properties that get overridden by the camera system evaluation. So this change also tweaks the categories and metadata on a few properties to make sure this component is hidden from the actor's Details View.

  • Expand documentation and add UI min/max settings to the field of view node.

  • Add explicit checkboxes to the lens parameters node Instead of specifying zero or negative values to indicate that some property should be ignored, there are now explicit checkboxes to enable/disable each lens parameter.

  • Add support for first person view.

    • Add new properties to the camera pose for 1P views.

    • Add a new 1P node to set those properties.

  • The node parameter detail customization now supports several property metadata like min/max values or units.

  • Add option to run camera directors and Blueprint camera nodes in editor.

  • Add action that aims at an actor with optional bone/socket.

  • Add a time-out property to camera actions Also simplify a bit how actions get cleaned-up, and the properties that need serialization.

  • Extract most of the "Aim At" action logic into a base class to make it easy to create other types of aiming actions.

  • No longer finds referenced objects from too many packages when gathering director usage The StateTree and Blueprint directors figure out what camera rigs and proxies they use by simply looking at referenced objects up to a certain distance.

    • However, this reference gathering was a bit too heavy handed. This change skips compiled packages, and adds an option to not explore objects of certain classes. This helps drive down the amount of referenced rigs and proxies shown in the "family shortcuts" in the editor (which showed seemingly unrelated assets).

    • It also fixes a bug with camera assets being dirtied on PIE because they would find new rigs to add to the default parameters when upgrading old data to the new interface.

  • Improve debug info for player controller/view target setups Add information about viewport size and aspect ratio.

  • Add screen-space framing option on the Aim-At camera action.

    • Adds a Target Framing property for where to frame the target on screen.

    • Use the new 2-bone IK function that takes into account an offset from the centre camera aim.

    • Improve the debug rendering a bit with extra information about the aiming.

    • Change the default lock-on tolerance to be a bit looser.

  • Remove GetTargetAngles and use proper projection/unprojection for all of the framing nodes' logic.

    • Make the dolly and panning nodes use projection/unprojection for computing how to recompose their shots.

    • Add more utility functions for projection/unprojection.

    • Make the projection/unprojection functions handle non-default aspect-ratio axis constraints.

    • Fix some issues in GetEffectiveFieldsOfView where it didn't correctly account for non-ideal aspect ratios.

    • Remove FCameraFramingMath which isn't used anymore.

  • Move the CameraPose-to-MinimalViewInfo code for easy re-use.

  • Add icons for Camera Rig Actor and Component.

  • Remove extra root node event API Reimplement the evaluation service's `OnRootCameraNodeEvent()` API in terms of the existing event that exists on the root node evaluator. This removes a bit of core API that wasn't needed.

  • Make the easing blend type a BlueprintType.

  • Update unit tests following changes to camera assets.

  • Fixes and improvements to the interface parameter panels.

    • Better default names for newly added parameters.

    • Support keyboard shortcuts for renaming and deleting parameters.

    • Add a button to delete selected parameters.

    • Properly refresh the list of parameters when undoing/redoing an add or delete.

  • Clean-up and improve handling of driven camera node parameters and multi-level prefabs.

    • Unify a bunch of code handling reflection-based node parameters vs custom node parameters (those obtained through the `ICustomCameraNodeParameterProvider` interface). Now there's the `FCameraNodeParameters` class that can build a list of available parameters on a camera node. This dramatically reduces the code in the Camera Rig builder class.

    • Fix some issues with multi-level parameter overriding, such as when an exposed parameter is re-exposed a level higher. Also, automatically flag connected prefab parameters as "overriden" on the prefab camera node to make sure those overrides are taken into account.

    • Rename some properties on custom parameter infos and interface parameter objects to be a bit clearer: "ParameterType" should be only for the parameter definitions, to specify if a parameter is "blendable" or "data". We should use "VariableType" for the type of variable to use in the variable table.

    • Simplify some of the parameter override helper code and remove unnecessary helper methods.

    • Add some unit tests for multi-level prefabs.

  • Add ways to parameterize post-process settings.

  • New "aim-at" camera action This action aims the current active camera rig instance towards a given target. It has options for keeping the lock on the target indefinitely until the action is stopped. The code for IK-aiming and other rotational corrections has been refactored so it can be used in the new action too.

  • New "lock user input" operation This operation locks user input for one frame.

  • Make value interpolators into constructable objects in Blueprints.

  • When a Boom Arm or Spline Orbit node doesn't have an input node, use a Driven Control Rotation node Before, these nodes were handling input themselves by querying the Control Rotation themselves. Now they use the seemingly better Driven Control Rotation logic. Also implement missing serialization of the boom arm length interpolator in the Boom Arm node.

  • New camera action service Camera actions are ways to execute operations on one or more running camera rig instances. They effectively "wrap" the root node evaluator for a camera rig, allowing arbitrary logic to be run before and after a camera rig evaluates. Camera actions also come with a few built-in options, such as the ability to clone themselves when a new camera rig activates, allowing a particular operation to persist over a long time.

  • Expose the blend type as a data pin on the easing blend node.

  • Make separate "getter" nodes for camera parameters, describe their connections in more general way.

    • Camera parameters were previously objects that doubled as their own node. This prevented driving two or more camera properties with the same parameter. This change removes the "node" aspects from camera parameters and adds a new "getter" node for that. The "getter" nodes point bac to the parameter they represent.

    • Previous data is gracefully upgraded for camera parameters that were present as nodes.

    • Since parameters may be connected to multiple pins, we can't determine their default value from that anymore, so the parameter has its own value now, a bit like variables in Blueprint. This changes a few things regarding the build process. A new customization class allows showing that default value in Details View for the user to set. Other parameter options (like "pre-blended") are removed from the list-view in the parameters panel: Parameters are now meant to be tweaked in the Details View.

    • Parameters can be added in transition graphs, for driving properties on blend nodes and such. A new base schema class provides support for this (a lot of its code is moved from the the camera node tree graph schema).

    • Actions for adding or auto-wiring parameters are changed accordingly (they now deal with the "getter" node mainly).

  • Make the search feature in camera editors based on the edited graphs and not the underlying object model Previously, searching through camera node or transition graphs was done based on the underlying object trees. Now, we more simply search the graphs that have been created out of these objects (thanks to UObjectTreeGraph). This makes it possible to get search results that are only indirectly related to the underlying data model, such as extra nodes and pins that show up in the editor.

  • No longer renders two debug infos when a GPC camera manager is running with a nested standalone GPC camera component Since the camera manager and the view target were both considered as the site for the "default" camera system, the camera debugger would end up drawing them on top of each other. Now we only consider the view target as default if the camera manager doesn't already run a camera system itself.

  • Activate and deactivate the output camera component along with its parent This fixes problems where a deactivated Gameplay Camera/Camera Rig component is still picked up by the engine when its owning actor is set as the view target, even though there's another active camera component on that actor.

  • Add option for freezing previous camera rigs when activating a new one.

  • Unify how Guids are generated for various assets.

  • Occlusion material node now supports skinned meshes and attached components.

  • Make sure components' parameter overrides are up-to-date with the referenced asset Update parameter overrides struct when starting evaluation, and on cook.

  • Add parameter GUIDs as tool-tips in the interface parameters panel.

  • Auto-rotate input node now supports going towards a zero rotation.

  • Boom arm node now supports additive rotation mode.

  • Improve how we apply parameter overrides from asset references Remove the need to keep the cached copy of the parameter overrides to detect changes: instead, just compare the new override values to the values found in the variable and data tables.

  • Add basic natvis support for the context data table.

  • Add easing blend node.

  • Make the boom arm and collision push node evaluators extensible.

  • Clean-up how components and player managers interact Simplify the camera component:

    • It now has an option to either run its own camera system ("standalone" mode, which is the default) or only run a camera evaluation context.

    • Remove some of the old code that attempted to handle a mix of both cases (such as with the non-immediate deactivation code) Simply the player camera manager:

    • Now anything that is set as the view target is run as a "blackbox", whether it's an arbitrary actor or vanilla camera actor or procedural camera (in which case it's better to use the aforementioned "standalone" mode).

    • To use fancier features such as blending or children directors, the procedural camera must be activated using dedicated new methods such as "Activate Gameplay Camera". Other clean-ups:

    • Move and improve on all the methods to activate/deactivate rigs and rig modifiers, and start/stop shakes.

  • Add Blueprint function for checking the validity of a shake instance ID.

  • Cleanup live-edit node listeners after a GC pass.

  • Make perlin noise use cubic splines by default This fixes undesirable "mini-pauses" in the middle of some curve segments when using a standard smooth-step interpolation.

  • Add more Blueprint methods to the components for managing persistent rigs and shakes.

  • Change how auto-build for PIE works to prevent packages from being modified at the wrong time.

    • Building a camera asset may change its data and dirty its package, but the previous method was doing when we were already inside the PIE world.

    • This change uses the same method as Blueprints, StateTrees, and so on, by using the BeginPIE delegate along with typed object iterators to gather objects to process just before PIE starts.

  • Add output return value pin to BP parameter setter node.

  • Add BP node function to get the owning rig.

• Network Prediction Plugin

  • Integrated time dilation feature to shrink input buffer size once network conditions improve.

  • Removed code related to physics integration that has been unsupported for a long time.

  • Added Iris replication support to the Network Prediction Plugin, while maintaining compatibility with non-Iris replication.

• Chaos Mover

  • Add optional server inputs for server side launch and other effects.

  • Stop applying angular velocity to target if the character should not remain upright and add option to never apply angular velocity to target in a falling mode.

  • Added some improvements for pushing into small, low objects.

• Game Input: Add haptic audio endpoint support via WASAPI and audio submix endpoints, just like the WinDualShock plugin.

• Add a new "Input Device Registry" (FInputDeviceRegistry) FInputDeviceRegistry is a thread safe registry to keep track of a FInputDeviceId to its name and type. This will make FInputDeviceScope obsolete. The registry is populated upon device connection and FInputDeviceId assignment, opposed to FInputDeviceScope's requirement of an actual input event call on the message handler being necessary.

• Adding MovementInterface meant to be used by various movement systems. By design it is very simplistic and helps with broad and common uses like gathering velocity, location and updated uobjects.

• Allowed conversation task nodes to choose branches in a specific order when advancing the conversation instead of always choosing a random branch. This makes it easier to set up progressive dialogue branches, e.g. a different branch based upon quest progress. Previously, each branch would need to have mutually exclusive conditions otherwise multiple branches would be possible and one would be randomly selected.

• In the Game Input plugin, make it possible to ignore or filter out devices from game input based on a VID/PID combo or their device family.

• Add a "preferred input API" setting to the engine. This will allow games to slowly roll out a change from an older input APIs like XInput to a more modern one like GameInput. The intent is that you could have a setting in your game, similar to a rendering setting for choosing which API to use, where players can enable/disable different input APIs to achieve the best compatibility for their setup. This has the added benefit of being able to "upgrade" a live project to use a newer input API with a fallback option via the config system.

• Spline Optimizations + Early out of SetClosed if it's already true. + Avoid re-constructing the TSet of normalized knot values in GetNearestAvailableKnotValue as this was being done repeatedly in GenerateDistanceKnotsForBezier. Reduces cost of GenerateDistanceKnotsForBezier by 90%. + Update FNewSpline::RebuildLegacyCurves to cache the attribute channels as these lookups were expensive. Also replace insertion sort of the rotation/scale points with a final sort at the end. + Add nullchecks when accessing scale/rotation attribute channels to prevent crashing when those channels are removed.

• Deprecate the Raw Input plugin in favor of the newer Game Input experimental plugin.

• Added support for dynamic (added at run-time) ability triggers to be used with abilities.

• Game Features: Made UGameFeatureData::GetDisallowedClasses() virtual so game project subclasses can prevent some Game Feature Action classes from being selectable.

• Converted Characters, Character Movement and dependent functionality to use a UObject representation of Movement Bases instead of UPrimitiveComponents. This opens up movement bases to non-actor objects such as FastGeoStreaming objects or Scenegraph objects.

  • ACharacter, UCharacterMovementComponent and other classes listed above have multiple examples of how to network and use this new struct, as well as examples of converting existing functions to use the new struct. See any function in the CharacterMovementComponent (such as UCharacterMovementComponent::RevertMove) as a good example of the new functionality.

  • ACharacter::OnRep_ReplicatedBasedMovement() shows a decent example of how to network and create this new struct from a UObject using MovementBaseUtility::GetMovementBaseDataFromPhysicsOwner.

  • FMovementBaseInterfaceData houses a UObject PhysicsObjectOwner and IPhysicsBodyOwnerInterface that implements necessary functions for basic movement base functionality.

  • FMovementBaseInterfaceData replaces UPrimitiveComponent as how code interacts with movement bases but a UPrimitiveComponent can be used to make a FMovementBaseInterfaceData easily as UPrimitiveComponent implements the IPhysicsBodyOwnerInterface interface and is a UObject so it is both the PhysicsObjectOwner and BodyInstanceOwner.

  • This change modified important classes/structs such as ACharacter, UCharacterMovementComponent, FBasedMovementInfo, FCharacterNetworkMoveData, FClientAdjustment and MovementBaseUtility with deprecation and fixup so they properly use new FMovementBaseInterfaceData struct. So any code extending the CharacterMovementComponent or code dealing with FBasedMovementInfo will likely need to be fixed up to support the new struct.

Bug Fix:

• Mover

  • Fix bug where skipping vertical anim root motion was not being respected in all montage cases.

  • Fixed inconsistent behavior during mode-changed events and the possibility of a queued mode getting ignored.

  • Fixed bug where sim proxy movement resulted in poor motion of any attached rigid bodies, such as ragdoll.

  • Fixed bug where activation of scheduled layered moves and instant effects would occur 1 frame late on variable-tick configurations.

  • Fix bug where a montage's RateScale was not respected during root motion layered moves.

  • Fixed issue with stale floor information causing teleportation-like behavior.

  • Disallow more than one active root motion montage layered move at a time.

  • Fixes crashes that can occur when compiling a MoverComponent BP while PIE is running with an instance of it.

  • Fixed sim proxy montage time drift that was causing divergence with root motion animation playback.

  • UMovementUtils::ComputeVelocity now limits velocity input to max speed properly.

  • Fixed issue where residual spring state persisted after interruption, such as during a root motion montage.

  • Fixed issue where sim frame counts in trajectory prediction were always starting from zero, and added optional start time/frame to the prediction params.

  • Fixed crash that could occur if there was a rollback before BeginPlay completed.

  • Fixed bug where an invalid up-direction would result in any gravity override being turned off.

  • Step Up/Over functions now track and return movement time so we can properly keep track of it in movement modes. This fixed an issue in walking transitioning to falling that launched the character.

  • Initializing some FollowPathMode data in mode Activate so we guaranteed run it on servers and clients. This fixes a bug where control points sometimes never get initialized in forward predicted movement.

  • Fixed crash when using User-Defined Structs in a Mover data collection when Iris networking is enabled.

  • Fixed crash that could occur when dragging and dropping an asset into an already-running PIE session.

  • Fixed crashes that could occur when editing properties of a MoverComponent at runtime through the editor Details panel.

  • Fixed bug where the Play Montage BP node would find the first mesh component instead of the primary visual component.

  • Adding read write lock when Queueing LayeredMoveInstances.

  • Fixed issues when trajectory prediction was queried before MoverComponent was finished initializing.

  • Fix UNavMoverComponent::GetFeetLocationBased nullptr MovementBase access and invalid supplied data causing occasional EPathFollowingResult::Blocked for AI agents due to bad samples.

  • Fixed up incorrect UE_REQUIRES arguments in GetMoverComponent and GetMoverComponentChecked functions in MovementModes.

  • Fixed bug where a tag cancellation request would cancel a layered move that was queued later during the same frame.

  • Fixed bug where continuous corrections could occur when transitioning from a skeletal mesh base with a valid bone to a static mesh.

  • Fixed bug where simulation events with timestamps close to each other could be processed out of order.

• Enhanced Input

  • Prevent triggers from re-firing after FlushPressedKeys while key is held.

  • Fix a long standing Enhanced Input issue around input triggers and modifiers not correctly maintaining their state when RebuildControlMappings is called.

    • Now when control mappings are rebuilt, if a key mapping already existed and its modifiers/triggers have not changed, each UInputTrigger and UInputModifier will call a "OnReinstanced" function (OnTriggerReinstanced and OnModifierReinstanced respectively).

    • This provides triggers and modifiers the chance to copy over any state that needs to be preserved across key mapping rebuilds. You can also implement these functions in custom Blueprint trigger or modifier classes by overriding the "Receive Reinstanced" functions.

    • This fixes bugs such as "Down" triggers having their input events re-fired every time the control mappings are rebuilt, even though you have not yet released the key.

    • This also fixes some issues with input modifiers which maintain state over time, like smoothing modifiers that want to keep track of the last used input value. This also fixes an issue with key mappings which _are_ actually new, and did not respect the bIgnoreAllPressedKeysUntilRelease flag. Now, new mappings will correctly be ignored if they are down when an IMC gets added and has a mapping to them.

  • Fix a bug where key mappings would not correctly be ignored if the input was just flushed (for example, by changing input modes between Game and UI for the player controller).

  • Fix mappings to AnyKey getting into a broken state when mouse scroll wheel up/down were used.

  • Enhanced Input: For boolean input actions mapped to touch Fkeys (FKey::IsTouch), the X,Y values of the keys will be the screen coordinate position. This means that a boolean input action will always evaluate to true, even after the touch has been released. To fix this, have Enhanced Input check the key state's bPressed value instead of the raw X,Y value in UEnhancedPlayerInput::PrepareInputDelegatesForEvaluation. This will ensure that touch FKey values have the expected trigger state flow and are calculated correctly in the IsActuated function of UInputTrigger.

• Mover Examples

  • Fixed crash that could occur if FollowSplineMode had a bad/missing spline actor during setup time.

  • Improving handling of orientation intent when not orienting to the movement direction.

• GAS

  • When marking abilities as garbage, also mark any SubObjects of those Abilities as Garbage. LyraGameplayAbilities can have SubObjects that must be MarkAsGarbage with their Outer.

  • Fix for GEComponents accessing other UObjects during PostInitProperties while AsyncLoading is enabled.

  • Using Generic Replication, the GameplayTagCountContainer could get stuck in a state where it constantly replicates a None tag if any of the tags were set to non-replicated.

• Cameras

  • Detail customizations for CineCameraComponent presets were not correctly checking IsEditable on the properties, and missing applying some new properties.

  • Fix rewind debugger crash when recording post-process settings with weighted blendables.

  • Fix missing pin on nodes in camera shake graphs.

  • Fix DPI scaling issue in debug renderer.

  • No longer asserts when (re)activating a Gameplay Camera component that is already active.

  • Fix issues with camera actions started on the same frame camera rigs are activated When a camera rig instance is pushed on the main blend stack on the same frame that a camera action is started, that action could be created on the previously active camera rig, resulting in incorrect behaviour as the action only affected the camera rig that was blending out. This change therefore starts actions in a "pending" state where we don't create the action evaluator until after the camera director has run. To make this possible, evaluation services have a new callback for evaluating between the camera director update and the root node update. Added new unit tests for camera actions.

  • More fixes for not modifying assets during load/build unless warranted.

    • The code that upgrades old Camera Asset parameters to the new interface needs to reproduce the old bug that even non-visible parameters were included :(.

    • Non-visible parameters don't have the CPF_Edit property flag, so also patch that when loading data in the version of the engine that didn't handle property flags in property bags.

  • Fix regression bug about camera node parameters being incorrectly built when they use a camera variable asset.

  • Make sure the "aim at" action uses the shorter rotation to accomplish its goal.

  • Fix assert sometimes firing after rebuilding a camera rig When a Camera Rig Component is selected in the level editor, it shows up in the Details View and the customization for the Camera Rig reference is active. When the referenced Camera Rig is rebuilt, that customization automatically updates the reference's parameters property bag. So when the component itself ends up receiving the build notification, the reference's parameters are up to date. This prevented the component from reinitializing the evaluation context, and could lead to asserts if new parameters were added, since those entries wouldn't exist in the variable or context data tables.

  • Fix missing code path for connecting to struct data properties.

  • Remove calls to Modify() from PostLoad()

  • Fix incorrect pragmas.

  • Fix assert on running a Camera Rig component This is a fallout of a previous change -- the generated Camera Asset in a Camera Rig component didn't have the correct allocation info anymore for initializing the evaluation context's variable and data tables.

  • Fix unity builds potentially leading to symbol redefinition.

  • Fix asset dirtying problems between camera rigs and camera assets The first problem is that camera rigs build all the allocation information they need, including the memory needed for their evaluator tree, and the entries they need in the variables/data tables.

    • This can easily mark a camera rig asset as modified, when:

      • (1) evaluator classes change (e.g. a new field is added) or

      • (2) when a referenced camera rig, such as a prefab rig, changes in a way that affects its own allocation info.

    • This ends up prompting the user to re-save assets that they haven't touched, with no obvious reason why. So the solution to this is easy: only build allocation info during cooking. In non-cooked builds, we just allocate things as we go, which is less performant, but much better for the user.

    • The second problem is that camera assets were automatically gathering all the exposed parameters from all their referenced camera rigs, and using that as their own exposed parameters. This was simple and functional at first, but it also created the same problem: the camera asset would get flagged as modified when any referenced camera rig had new/changed/deleted parameters. This again prompted the user to re-save the camera asset for no good reason.

    • In addition to that, as camera assets grew in scope, they could start getting a lot of parameters that the user didn't necessarily want. Solving this problem requires a new workflow: the camera asset editor now has an "Interface Parameters" panel, similar to the camera rig editor. It lets the user add/remove parameters on the camera asset itself, and specify how each of these parameters binds to which camera rig's parameter. It effectively removes the automatic step of gathering all referenced camera rigs' parameters, and replaces it by a manual step where the user can pick and choose which parameters to expose on the camera asset. This way, modifying a referenced camera rig doesn't modify the camera asset: the user has to explicitly modify the camera asset if they want its interface to change. Other notes about this change:

      • All the builder classes and methods now pass around a base "build context", which contains information about whether we're cooking or not.

      • Camera assets are upgraded on build or open to get a default list of interface parameters that reproduces what was automatically built before.

      • When initializing a new camera rig instance, we now ensure that the variable/data tables have all the entries needed. This makes uncooked builds work by lazily allocated memory when we don't have the allocation info.

      • The camera director's GatherUsageRigInfo now does extra stuff out of the box, such as looking into the proxy redirect table, and removing unwanted things from the output.

      • The code that converts a variable/data entry info a graph editor pin type has been moved into a common place for reuse.

  • Move easing blend node to the correct directory.

  • Fix some edge cases with the context data table.

    • Prevent access to some template functions for enum types when it can return pointers to incorrect underlying int size.

    • Add some extra checks to array setters.

  • Continue recording debug info even when a camera system doesn't have any evaluation context active.

  • Fix bugs related to enums in the data table.

    • Store enums with an int32 for handling large flags enums.

    • Fix a bug where we have to convert the value (not the pointer) of a data table entry in the case of enums, which may have different backing types.

    • Also fix incorrect data traits for strings.

  • Fix incorrect FOV when using a vanilla camera component or actor as the view target inside a GPC camera manager When setting the FOV or focal length on a camera pose, we always need to invalidate the other so that both aren't defined at the same time.

  • Ensure we continue handling collision results events when we don't hit anything This fixes a regression where absence of collision would lack updating the damper to return back to the "rest" position.

  • Fixup default parameters on load as a workaround for a bug in FInstancedPropertyBags.

  • Fix possible crash when clearing the camera asset or camera rig asset on a component.

  • Protect panning framing node from introducing NaN rotations.

  • Fix some problems with the screen-space framing nodes.

    • No longer stops reframing once the target is in the dead-zone, keep following it if it's still moving.

    • Modulate the reframing based on the disengagement time to get a semi-random rest position inside the dead-zone.

  • Get rid of the debug info if we don't need it anymore This fixes a bug where editor visualization stops working if the user activated debug display once.

  • No longer offers to create graph nodes when going "up-stream".

    • Also, it caused an undo bug since, after creating a node of the same type, the schema was trying to connect that to the dragged pin (the "self" pin on the first node). Which isn't possible. So it would fail, which would cancel the connection transaction, which would cancel the creation transaction. But the creation happened, so it made the creation of the (useless) node non-undoable. Now we just don't offer to create it anymore.

    • The ObjectTreeGraph model is mostly meant to go from "left to right", i.e. from an object to its properties to the objects connected to these properties. Dragging the "self" pin to the left only offered to create the exact same node type because that's the only node type compatible with itself generally (unless there are subclasses in existence). So it's mostly useless.

  • Fix how the output camera component is created.

  • Fix possibly incorrect evaluation layer when starting a modifier rig.

  • Fix logging formatting.

  • Fix missing sub-object destruction in gameplay camera component.

  • Look for rigs and rig proxies used by directors more than one package away This fixes the issue of, say, a Blueprint director using some data table or chooser asset for selecting rigs, which meant that the "family shortcuts" and other things using the UsageInfo API had incomplete info.

  • Fix crash when opening the Blueprint palette The palette creates "template nodes" that aren't actually fully initialized, and are prevented from loading any data.

  • Fix double-negation and incorrect comment.

  • Fix GetActiveCameraRigEvaluationInfo returning the wrong information when rigs are blending.

  • Fix camera variable overrides not working in PIE In editor/PIE builds, the camera asset's AllocationInfo (variable and context data tables) is only populated at cook time, so it is empty when running in-editor. This caused GameplayCameras component overrides to silently fall back to default values. When AllocationInfo is empty, we now gather it transiently from the camera rigs at runtime, mirroring what CameraAssetBuilder does during cooking. Cooked builds are unaffected and continue to use the pre-computed AllocationInfo as before.

• Chaos Mover

  • Fixed the calculation of inverse inertia when applying jump reaction impulse. This ensures the correct impulse is applied when jumping from dynamic objects.

  • Fixed bug in pathed movement mode where looping could behave incorrectly.

  • Updated the ground check query sweep in falling mode to account for the updated velocity. This prevents fast moving characters falling through the ground.

• CMC: Prevent unexpected upwards velocity boost when jumping/falling upwards into an acute angle corner of steep walls.

• Level Streaming Persistence plugin: Fixed crash when persisting properties on a map placed actor that got destroyed but is part of a reused level instance.

• Fix an operator discrepancy in UEnhancedPlayerInput::AddMapping. Use the.Equals function instead of operator== on FEnhancedActionKeyMapping when adding mapping to enhanced input.

• Fix crashes when game feature plugins caused a garbage collection at a bad time, it now always performs the garbage collection at the end of the frame.

• Fix issue where trying to unregister an asset from a temporarily-unregistered DataRegistry would fail, causing GC leaks when the data registry is reinitialized later.

• Upon device connection, populate data in the UInputDeviceSubsystem about the given device if a valid FInputDeviceScope is available. This makes it a bit easier for gameplay code to query the input device subsystem when connection events happen instead of needing to wait for the user to actually press an input for it to be populated.

• Circular buffer: Reduced checked capacity limit that was too high.

• Multi Server: FPredictionKeys should always send full data when communicating with a proxy.

• Fixed assertion in FVisualLogger::CleanupRedirects.

• Fixed bug that would propagate stale CurrentEventData to future ability calls that received a nullptr CurrentEventData during activation.

• Fix bug where the tick manager could get deadlocked in EndPhysics because it failed to properly flush the manual dispatches.

• Fix issue where AsyncSaveGameToSlotForLocalPlayer would ensure if called twice in a row. It now sets the LastSuccessfulSaveRequest to the request that actually completed instead of the last requested.

• Fix ScalableFloats to correctly reset cached curve when serializing or copying. This fixes issues when used in inherited Blueprints.

• Fix several issues with C++ defined gameplay tags when a game feature dll is loaded after startup. Fast tag replication cannot support this case but Dynamic tag replication should now work correctly with late dll loads.

Deprecated:

• Improve comments for tick functions to correctly indicate thread safety, and deprecate GetLastTickGameTime because it was confusing.

• Enhanced Input: Deprecate the combo trigger. This trigger type is unreliable and can cause mapping contexts to be corrupted in the editor.

Mass

New:

• Mass Trace

  • Add missing trace events for archetype creation and entity moves during archetype splitting in MassEntity Introduce a batch UE_TRACE_MASS_ENTITIES_MOVED macro to trace multiple entity handles in a single call.

  • Extract MassInsights trace provider and analyzer to new MassDeveloper runtime module. Move FMassTraceProvider, FMassTraceAnalyzer, IMassTraceProvider, IEditableMassTraceProvider, and all supporting data types (FFragmentInfo, FArchetypeInfo, FEntityEventRecord, FRegion, FRegionLane, etc.) from MassInsightsAnalysis plugin to Engine/Source/Runtime/Mass/MassDeveloper under the UE::Mass::Trace namespace. Port all MassInsightsUI consumers to the new types. Simplify module entry point via SetupMassTraceAnalysis() factory function.

  • Add Sparse, ConstShared, and SparseTag fragment types to MassInsights and MassEntity tracing Include shared and sparse elements in archetype registration trace output Check derived types before base types in fragment type classification to avoid incorrect matches.

• Mass Commands

  • Extend fragment instance and build commands to support mixed element types in a single entity move New commands:

    • Add FMassCommandAddElementsWithSharedFragments<TTypes...> for composition-only changes + shared fragment values in one move.

    • Add FMassCommandAddFragmentInstancesWithSharedFragments<TShared, T...> for fragment values + shared values in one move.

    • Add convenience methods on FMassCommandBuffer: AddElementsWithSharedFragments, AddFragmentInstancesWithSharedFragments Extend existing commands to accept tags and sparse types:

    • FMassCommandAddFragmentInstances<T...> now accepts FMassTag, FMassSparseTag, FMassSparseFragment alongside FMassFragment.

    • FMassCommandBuildEntity<T...> same mixed-type support.

    • FMassCommandBuildEntityWithSharedFragments<TShared, T...> same mixed-type support.

    • Tags included in composition, excluded from value payload (GetAsNonTagGenericMultiArray).

    • Sparse types handled in-place via BatchAddSparseElementToEntities before composition changes EntityManager API additions:

    • BatchChangeCompositionForEntities overload with FMassArchetypeSharedFragmentValues.

    • BatchAddFragmentInstancesForEntities overloads with FMassTagBitSet and/or FMassArchetypeSharedFragmentValues.

  • Unify Add/Remove commands with FMassCommandAddElements and FMassCommandRemoveElements.

    • Add FMassCommandAddElements<TTypes...> (PushCommand batching) and FMassCommandAddElementList (PushUniqueCommand) for adding any mix of fragments, tags, and sparse elements in a single entity move.

    • Add AddElements convenience methods on FMassCommandBuffer (templated and runtime).

    • Redirect AddFragment, AddTag convenience methods to FMassCommandAddElements.

    • Deprecate FMassCommandAddFragmentsInternal and FMassCommandAddTagsInternal.

    • Add sparse element support to FMassCommandAddFragmentsInternal and FMassCommandAddTagsInternal by splitting sparse types to BatchAddSparseElementToEntities.

    • Add check in BatchChangeCompositionForEntities rejecting shared/chunk/sparse on Add side.

    • Add chunk fragment rejection in BatchAddElementToEntities and AddElementToEntity.

    • Fix CheckBreakpoints signature on AddElements and RemoveElements to match composition-only usage (entity-only, no fragment instances).

    • Add unit tests for chunk/shared/sparse Add-side gaps.

  • Add bitset-level and runtime type validation for Mass element composition.

    • Shadow GetTypeBitSet<T>() in DECLARE_NEWTYPEBITSET to static_assert that T matches the expected element subtype, not just FMassElement (root cause fix for typed bitset accepting wrong element types).

    • Add testableCheckf guards in BatchChangeCompositionForEntities to validate that ElementsToAdd and ElementsToRemove contain only tags and fragments, catching misuse before it reaches InitializeWithSimilar.

• Extend BatchRemoveElement to support shared fragments and add unit tests.

  • Extend IsElement() to accept shared and const shared fragment types.

  • Extend BatchRemoveElementFromEntities and RemoveElementFromEntity to dispatch shared and const shared fragment removal via new InternalBatchRemoveSharedFragmentsFromEntities.

  • Add testableCheckf to Add element APIs rejecting shared fragments with clear message.

  • Add unit tests for FMassCommandAddElement/FMassCommandRemoveElement covering tags, fragments, shared fragments, const shared fragments, mixed types, and negative cases.

• Additional archetype information (list of elements, list of entities) retrieval.

• Added a single call to check fragments or tags or in an archetype.

• Mass trait validation errors now highlight the trait net mode to help pinpoint the issue.

• Queries can now return a topology hash for their archetypes.

• Added UMassRepresentationActorManagement::IsActorReadyForRepresentation, a virtual hook (default returns true) used to wait for actor readiness before switching off ISM. While the hook returns false the processor keeps the ISM/SkinnedMesh visible and the spawned actor disabled; game-side subclasses can override it to gate the transition on async asset streaming. The wait is bounded by the ai.massrepresentation.MaxActorVisualReadinessWaitFrames cvar (default 255), after which the actor is force-enabled and a warning is logged.

• Added trajectory generation and spring movement code to MassGameplay (experimental) Mass Traits:

  • U Spring Movement Trait: Adds spring-damped movement.

  • U Trajectory Trait: Adds trajectory generation.

  • U Trajectory Movement Trait: Overrides movement to follow trajectory.

• Removed MassEntity's dependency on AITestSuite. The testable-ensure mechanism (global counter + 3 macros) was moved into MassCore itself, so it no longer pulls in AIModule and GameplayTasks through a Developer module.

• Mass Debugger: Added SparseElement bitset to the archetype details Note that the information exposed is the aggregated info from all chunks; it doesn't mean that all entities have the element.

• Modified UE::Mass::Utils::CreateEntityCollections to handle the common single-entity input case, and to perform better when multiple entities of the same archetype are processed.

• API Change: Made the FMassArchetypeCompositionDescriptor(const FMassElementBitSetand) constructor non-explicit, in preparation for the near-future removal of FMassArchetypeCompositionDescriptor.

• Mass Gameplay Debug: Made AssignDebugVisProcessor editor only to prevent useless registrations on non-editor builds Also made sure it is properly setup for registration when WITH_MASSGAMEPLAY_DEBUG i s0.

• Mass Entity: Add observer support for shared fragments and swaptag.

• Added the missing FMassCommandRemoveElement command.

• API Change: Renamed FMassEntityManager::AddElementToEntities and RemoveElementFromEntities to BatchAddElementToEntities and BatchRemoveElementFromEntities respectively, for consistency with the rest of the API.

• Extended the MassEntityManager and Archetype API to support the use of struct views.

• Added a flag to EntityBuilder to force-committing always through Mass commands. Added the mass.EntityBuilder.ForceDeferredCommit cvar to set this behavior project-wide.

• Added a way to configure MassEntityTraits to be valid for a specific target configuration (Standalone, Client, Server, etc).

• Move Actors for entities spawned by AMassSpawner into an Outliner folder that matches the name of the spawner.

• Added Sparse Elements, along with support in queries, commands, and entity builder. Sparse Elements are Mass elements (tags and fragments) that can be added to entities without causing them to change archetypes — they are not part of an archetype's composition and are handled individually per entity.

• Renamed GetOrSpawnActorFromTemplate to GetOrRequestSpawnActorFromTemplate to reflect that the function requests a spawn rather than spawning synchronously. Declaration, definition, and all callers were updated.

• Exposed mass processing phase tick functions in public API to allow for setup of tick dependencies.

• TStructTypeBitSet changes to support "single element bitsets":

  • Alternative implementations of bitwise operators.

  • Default to 8 elements as bitarray's initial allocation size.

  • Modified some functions' signatures to support more flexibility.

Bug Fix:

• Fixed matches queries with Any fragments and tags to archetypes with only one or the other.

• Mass entity world subsystem now flushes remaining commands on deinitialization. This is required to cleanup any elements registered to other subsystems or rendering scene.

• Improvement: [Mass Representation] Switched two manually calculated bDoKeepActorExtraFrame branches to use the new UE::Mass::Representation::ShouldKeepActorExtraFrame helper. Bug Fix: [Mass Representation] Fixed the issue where the original conditions weren't respecting the value of FMassRepresentationParameters.bKeepActorExtraFrame.

• Mass Debugger fix: Struct redirects are now applied when pasting query JSON, mirroring the pattern in FInstancedStruct::ImportTextItem.

• Fixed an overzealous check in UMassAgentComponent::PausePuppet that crashed the function when called on a non-puppet. Switched the check to an ensure.

• Fixed: The Mass debugger running with an invalid entity.

• Fixed an issue in UMassSpawnerSubsystem::DoSpawning's BatchSetEntityFragmentValues when called in a loop with a single CreationContext — by iteration N the context included archetypes from prior spawns with different fragments. The call now builds a fresh local collection from just the current call's spawned entities.

• Fixed infinite recursion in FMassEntityConfig::FindTrait when the parent config chain contains a cycle.

• Fixed a MassAgentComponent assert when Iris destroys a puppet in the PuppetPendingReplication state. UnregisterAgentComponent previously had no handler for this state, so when Iris destroyed a replicated actor before its NetID replicated (e.g. on relevancy change) the component was stuck with no entity handle and no NetID. Added PuppetReplicationAborted() to cleanly bail out to None.

• Mass Debugger: Fixed wrong hierarchy representation of unnamed archetypes in MassDebugger by adding a composition hash identifier for unnamed archetypes and filtering out the None entry from debug names.

• Fixed `FMassCommandAddFragmentInstances` ignoring its `OperationType` parameter. The constructor accepted the argument but its initializer list hardcoded EMassCommandOperationType::Set, causing FMassCommandBuildEntity (which passes Create) to sort as Set during command buffer flush and hit a checkf on `entity state == Reserved`.

• Add stale model check to entity list refresh guard condition in Mass Entity Debugger.

• Fixed warning messages regarding undeclared subsystem access via FMassSubsystemAccess.

• Allow multiple registration of types with Mass, which avoids an ensure when using Mass from Game Feature Plugins.

• Removing CDOs from Mass settings on modules' unload.

• Fixed an off-by-one in CacheSubsystem where Subsystems.AddZeroed computed the wrong resize delta (Num() - SystemIndex instead of SystemIndex - Num()). The array is pre-sized in the constructor so this had not blown up in practice.

• World Condition: Fixed case where world condition queries would not be properly linked when embedded in a struct.

• Made naming spawned actors with the entity's GUID (when available) optional, and changed the default to false, since the previous behavior could cause unexpected issues.

• Fix for exporting struct array properties as json.

• AI Controller: We now end all tasks owned by the controller before calling OnUnPossess on the base class since those tasks might require access to the pawn's associated controller to exit properly.

Networking

New:

• Iris

  • Allow users to subclass UNetObjectPrioritizer easily.

  • Allow options to be passed to UE_NET_IMPLEMENT_NAMED_STRUCT_LASTRESORT_NETSERIALIZER_INFO and UE_NET_IMPLEMENT_NAMED_STRUCT_LASTRESORT_NETSERIALIZER_AND_REGISTRY_DELEGATES. Current options are to set the max quantized size, exclude from default state hash and custom fragment registration.

  • Added FInstancedStructNetSerializer delta serialization support.

  • Added the LogIrisCreationFlow log category to trace server-to-client root object creation timing across key Iris replication events, making it easier to correlate server and client logs and measure end-to-end object initialisation latency.

  • Fixing NetTrace to work with TailBuffer.

    • When active, the TailBuffer is constantly caching trace packets for the duration of a session. This means we need to ensure that each NameId is unique for the whole session, and also included in Important events to make sure there's no missing data.

    • It also means we may see multiple ConnectionCreated events with the same ConnectionId, as Traces aren't started/stopped in the same way when outputting a TailBuffer, so in the NetTraceAnalyzer we only update the ConnectionState the first time.

    • ResetLifetimeConditionDebugNames and OnResetPersistentNetDebugNames removed from the API as they are no longer required and would break the Trace Tail Buffer Fixing NetTrace to work with TailBuffer by keeping DebugNameIds consistent.

    • ResetLifetimeConditionDebugNames and OnResetPersistentNetDebugNames removed from Iris Net Trace API as they cause broken traces if Trace Tail Buffer is in use.

  • Added optional parameter to control if a subobjects child subobjects replicate before or after their parent.

  • ActorComponents still defaults to replicate their SubObjects before the components to not cause any unexpected divergences.

  • Clarified documentation.

  • Deprecated ESubObjectInsertionOrder::ReplicateWith in favour of explicitly specifying root and parent when adding a subobject.

  • Fixed bug where using ESubObjectInsertionOrder::InsertAtStart would shift conditionals around and apply them to the wrong subobject.

  • Added ensure if reliable attachementqueue is overcommited.

  • Implemented support to allow start and StopReplication being called multiple times for static objects including support for flush.

  • Refactored FlushLogic to be more robust and behaves closer to normal destroy.

  • Fixes issue where the same static NetRefHandle/Object could end up being replicated as multiple NetObjects/Channels causing bugs on client.

  • Fixed case where flush was not propagated properly to new connections.

  • Fix for ObjectPoller using the parent net stats rather than the passed in child net stats. Fixed a small chance of incorrect stats being generated when using NetStats with Multithreaded Iris Polling.

  • Replicated objects with creation links to other objects will replicate after creation dependencies before they replicate to reduce reordering on clients.

  • Implemented debug write pass for ReplicationWriter that writes NetObjects marked as debugobjects using separate packets not counting against bandwidth limit.

  • Added API for marking an object as a DebugObject.

  • Added API for allowing DataStreams to write DebugData that does not count against bandwidth limits.

  • Add a PreferredReplicationSystem setting to FIrisNetDriverConfig that can override the net.Iris.UseIrisReplication cvar for specific NetDriverDefinitions.

• Multi Server

  • Adding OnAllServersConnectedEvent as a potential Event to listen to.

  • LaunchMultiServer now supports -BotCount=XX which allows you to specify an overall number of bots which works in both -client=proxy and -client=direct mode.

• Iris Parallelization

  • Added API for network HandlerComponents to indicate support for being run in parallel. Enabled NET_ANALYTICS_MULTITHREADING so that OodleNetworkAnalytics can run in parallel Network HandlerComponents can indicate support for running in parallel per-connection. Enabled NET_ANALYTICS_MULTITHREADING by default.

  • Added API for network HandlerComponents to indicate support for being run in parallel. Enabled NET_ANALYTICS_MULTITHREADING so that OodleNetworkAnalytics can run in parallel Network HandlerComponents can indicate support for running in parallel per-connection. Enabled NET_ANALYTICS_MULTITHREADING by default.

  • Adding thread safety to NetworkMetricsDatabase and the related stats in NetDriver Added thread safety to NetworkMetricsDatabase and the related stats in NetDriver.

  • Make Net Tracing existing objects and object creation threadsafe. Added a SharedNewObjects list to temporarily store newly created objects in parallel net connection tick and then merge them with the full list after NetConnection Tick has completed. Net Tracing for object creation has been made thread safe for Iris Parallelization.

  • Make Net Tracing existing objects and object creation threadsafe. Added a SharedNewObjects list to temporarily store newly created objects in parallel net connection tick and then merge them with the full list after NetConnection Tick has completed. Net Tracing for object creation has been made thread safe for Iris Parallelization.

  • Added thread safety functionality to DeltaCompressionBaselineManager. Added FScopedBaselineAccess which guards parallel access to the BaselineManager, which is used in the ReplicationWriter in preparation for running it in parallel. Also renamed GetIsInParallelPhase to IsInParallelPhase to align with Iris Beta naming conventions. Added thread safety to DeltaCompressionBaselineManager.

  • Added thread safety to NetBlob, NetTokenStore, NameTokenStore, StringTokenStore and StructNetTokenDataStore

    • Added ExcludeParallelIrisSupport to TargetRules.cs so that licensees can remove these mutexes if they intend to run the server in single threaded and want a few nanoseconds of perf back.

    • Can be removed from compilation using ExcludeParallelIrisSupport.

    • Added UE_SUPPORT_PARALLEL_IRIS define which includes multithreading logic only on Server and Editor builds by default. Client only builds do not need the mutexes included as they will not run the replication logic in parallel.

  • NetConnection::Tick can be run in parallel on the server by setting net.iris.AllowParallelNetTick to true. UChannels can indicate support for parallelism in SupportsParallelTick Implemented thread safety for ObjectReferenceCache Iris replication supports parallel NetConnection Tick to run the write phase across multiple threads.

• Improved connection startup latency for numeric IPv4 addresses by sending the initial handshake packet in the same frame instead of waiting for the next-frame async resolution path. The net.NumericIPSyncResolve CVar can be used to disable synchronous resolution and restore the previous behavior.

• Added experimental NetworkServiceDiscovery plugin providing Windows/Mac/iOS/Android mDNS/Bonjour service announcement and discovery.

• Added a runtime CVar, HTTP.Curl.MaxHostConnections, to control libcurl's per-host HTTP connection limit and allow the concurrent request limit to be modified on demand.

• Add FScopedNetEmulationOverride class for easy, temporary network emulation overrides in test cases.

• FNetBitArray's ForAllSetBitsInRange is now handling invalid StartBit and EndBit parameters more gracefully.

• Net: Bumped default ServerDesiredSocketReceiveBufferBytes and ClientDesiredSocketReceiveBufferBytes to 262144 bytes to avoid dropping data if user does not override settings.

Bug Fix:

• Iris

  • Output the entire default state of replication state descriptors when encountering protocol mismatch errors.

  • Fix issue with destroyed object with destruction info being mistaken for a destruction info. Allow destroyed object with destruction info to be replicated if it needs flushing for example due to a reliable RPC being called the same frame it's added for replication.

  • Fixed memory leak in PolymorphicStructNetSerializer.

  • PlayerStates are now prioritized using the NetObjectCountLimiter with the PlayerStateCountLimiterConfig by default and as intended.

  • Fixed replication issues when connecting a standalone client to a PIE server.

  • Fixed internal leaks of subobjects being torned off.

  • Fixed filtering hysteresis bugs for late joining connections.

  • No longer stores instanced struct type in the InstancedStructNetSerializer default state as the client is not being able to resolve the type.

  • Fixed rare crash when enabling parallel polling.

  • Fix issue with newly created dependent object entering hysteresis despite parent being filtered out already.

  • Fixed issue with dependent objects potentially getting replicated when they shouldn't and vice versa.

  • Fixed bug where new objects assigned to a previously used internal index could end up not being properly polled on empty servers.

  • Fixed issue where out of scope objects being created and destroyed the same frame requiring flush would be destroyed using the wrong code path.

  • Only call SetActorIsPendingPostNetInit for actors that are expected to call PostNetInit.

  • Fixed issue where a static actor would skip their call to BeginPlay if they are in pending dispatch list and BeginPlay was issues on world triggered from OnRep of another actor.

  • Fixed issue with ObjectPoller not force polling ObjectReferences for pushbased fragments in mixed protocols after GC.

  • Fixed scheduling of dependent objects to not be reversed if spilling over to next packet.

  • Fixed bug where unicast rpcs did not respect RPCSendPolicy.

  • Fixed bug where replicated objects overcomiiting reliable attachment send queue was not properly marked dirty when queue could accept send more data.

  • Addressed issues with PacketNotification getting stuck in deadlock if both ends overshoots ack sequence history.

• Multi Server: Multi-Server Proxy uses GetLocalRole rather than GetRemoteRole as we are executing in the context of a Client (GetLocalRole is what the Server assigned us and GetRemoteRole is always ROLE_Authority).

• Corrected inconsistent initial conditionals in void AActor::GetReplicatedCustomConditionState() reversed compared to what is later set in AActor::PreReplication.

• Fix for DemoNetDriver crashes due to accessing memory in destroyed actors.

• Fix for issue where replayout did not respect net.ReplicateCustomDeltaPropertiesInRepIndexOrder and always replicated CustomDeltaProperties in RepIndexOrder.

• Fix StaticMeshActor instances not replicating when setting are applied on the instance instead of the Blueprint asset.

Learning Resources

Sample Content

New:

• Enabled HDR display support and added HDR display settings to Lyra.

Level Design and Art Tools

New:

• Hide RayTracing, Navigation, LOD, HLOD categories from SplineComponent : The spline component inherits them from the primitive component but is not renderable or navigable itself.

Bug Fix:

• Preventive fix for water brush against OnLevelAdded/Removed callbacks that can get called while the actor is unreachable.

• Fix GetDynamicWaterInfoCenter output Fix missing implementation of GetDynamicWaterInfoBounds.

• Fixed edit condition for water nav area class.

Geometry Core

New:

• Extended the FSubdividePoly Dynamic Mesh OpenSubdiv wrapper to interpolate all standard mesh attributes. Now e.g. UVs, skin weights, colors, etc will be interpolated when using Catmull-Clark or Loop subdivision in modeling tools or Geometry Script.

• General attribute support for FMeshSimplification.

• Generalize SkinWeightBinding operation to support 'constrained' binding, where vertices can only bind to a known subset of bones.

• Added a point-triangle distances connection method to vertex connected components, to help optionally join nearly-connected islands when computing mesh islands.

• Added vertex-based region of interest update paths to DynamicMeshComponent, matching the Triangle ROI paths + exposed these update paths to UPreviewMesh also.

• Added option for sparse point octree ParallelRangeQuery to also use a custom TFunctionRef to filter which bounds are relevant to the query.

• Added vertex and triangle selection versions of FDynamicMesh3's bounding box compute method (with similar logic to compute in parallel chunks).

• Added option for dynamic mesh overlay's per-vertex build to make the elements exactly 1:1 with vertices, so caller doesn't need to worry about the vertex to element ID mapping.

• The dynamic mesh's attribute set generic attribute accessor now returns nullptr if the attribute is not found, rather than failing a check(), to match how most of the other accessors work when requesting an attrib that doesn't exist.

• We now fill colors from hole boundaries in most hole fill operations (except smooth hole fill).

• Made DDC cache put responses return the record/value that the cache contains This can be used to detect conflicts between new and existing data, when not overwriting existing data.

• Added medial skeleton → hierarchical / animation skeleton conversion via minimum spanning tree.

• Added medial-axis sampling/skeletonization to GeometryAlgorithms.

• Added a method for VertexConnectedComponents to merge only the close vertices that pass some other filter, so e.g. one can only do this merge step for boundary vertices (which can be much faster than doing it for all vertices, and also can avoid connecting some intentionally-separated-but-nearby vertices) Added a thread-safe method for getting the cluster ID of vertex-connected components.

• Added a MeshVertexNormals method that can account for implicit welding -- i.e. a known mapping of some vertices to common weld vertices.

• Added a Sort() method to FIndex3i, to change the indices to a sorted order (ala the one already on FIndex2i).

• Improved the dynamic mesh simplification algorithm to be smarter about what edges can collapse. Added an edge constraint tolerance distance to optionally limit how far constrained edges can move during simplification.

• Added mult-label version of mesh iso curves cutting, via adapters to support arbitrary mesh types.

• Geometry Script and Modeling Mode mesh to convex hull nodes and tools now have a geometric tolerance for hull simplification, to allow simplification below the target triangle count when it will not introduce more error above the geometric tolerance threshold.

• AABB tree now supports meshes with FVector3f vertex storage.

• Added optional regularization to the QEM simplifier.

• Added optional scaling functions for the QEM simplifier metrics (quadric error, target length, and geometry error).

• F Sparse Dynamic Point Octree3: Export FindKClosestPoints function.

Bug Fix:

• Fixed a crash that could occur due to an edge case in the AABB Tree building logic.

• Fixed performance issue with MeshSelfUnion on meshes with many open boundaries by using pointhashgrid to filter potential edge matches in self union by midpoint. Also now check for edge vertex position matches in either ordering.

• Fixed issues with sparse dynamic point octree.

  • Fixed queries hanging on very large query bounds (by refactoring IterateRootsInRadius's logic to clamp query ranges and fall back to all-root iterations into a general root iteration helper)

  • Fixed points very near cell bounds crashing on insert due to floating point error making CellContains() not agreeing with the cell assignment. Now CellContains directly uses the cell assignment logic. Fixed issue w/ octree range iteration methods where we could potentially overflow the large-range test by casting to double too late.

• Fixed minimal hole filler accidentally passing the input mesh by value to the CheckIfEdgeFlipCreatesFlip helper function.

• Fixed crash in hole fill op where it could use reference a triangle with unset UVs.

• Improved edge collapse parameter interpolation for dynamic mesh's mesh simplification method.

• Fixed DynamicMesh CompactCopy checking the wrong mesh's attribute set for compactness. Fixed const correctness of IsCompact on attribute set.

• Fixed mesh simplifier's bad placement of boundary vertices (e.g. rounding off corners) -- it now considers error when picking boundary vertex position instead of always just picking the midpoint.

• Fixed the FModuloIterator struct ignoring StartIndex.